Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
[EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: | Oracle, for example, provides encryption functions, but the real problem | is the key handling (how to make sure the DBA can't get the key, cannot | call functions that decrypt the data, key not copied with the backup, | etc.). | There are several solutions for the key management, but the vendors should | start offering them. I would argue that the real problem is that encryption slows large searches (is percieved to slow large searches, anyway.) Adam Yes, encrypting indexed columns for example is a problem. But if you limit yourself to encrypting sensitive information (I'm talking about stuff like SIN, bank account numbers, data that serves as an index to external databases and are sensitive with respect to identity theft), these sensitive information should not be the bases of searches. If they are not he basis of searches, there will be no performance problems related to encrypting them. If they are indexes to external databases, then they are the basis of searches in those databases, by definition. My terminology might have been misleading. By indexes to external databases, I don't mean that the application that uses the database actually talks to the external databases (it doesn't use the info as a key to that external database) . Example: Cash_Ur_check is in the business of cashing checks. To cash a check, they ask you for sensitive information like SIN, bank account number, drivers licence number, etc. They use the information to query Equifax or the like to see if the person has a good credit rating, if the rating is o.k. they cash the check. They keep all the information in the database, because if the client comes back 2 months later, they will send the same query to Equifax to see if the credit rating hasn't changed. These sensitive information are indexes to external databases (but Cash_Ur_check doesn't directly connect to these other databases). Cash_Ur_check doesn't need to use these data as indexes. Cash_Ur_check can use first/middle/last name of person as an index, or attribute some random number to the person, or something else, they should not use the SIN to identify a person. They should not do searches on SIN to find a person given his SIN. Sure, but Equifax should. I have many other examples in mind, which I came across in the real world. So my answer to people that have the perception you mentioned is that if you want to encrypt sensitive information and that would cause performance problems, then there are problems with your data architecture privacy wise (you should re-structure your data, use it differently, etc.). Not a very satisfactory answer. No, of course I would sit down with the client and the software developers and examine their needs and constraints suggest how they can structure their data in a better way. I've done it several times over the years. There is no universal answer, but in my experience I found there is often good solutions. Let me throw back a precise question to you, to see if you disagree with what I said. Are you saying that it is often inevitable to index sensitive data? That is, are you saying that you often have to use sensitive data as the basis of searches? Yes. -- ApacheCon Europe http://www.apachecon.com/ http://www.apache-ssl.org/ben.html http://www.thebunker.net/ There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit. - Robert Woodruff - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
Ben Laurie wrote [EMAIL PROTECTED] wrote: Example: Cash_Ur_check is in the business of cashing checks. To cash a check, they ask you for sensitive information like SIN, bank account number, drivers licence number, etc. They use the information to query Equifax or the like to see if the person has a good credit rating, if the rating is o.k. they cash the check. They keep all the information in the database, because if the client comes back 2 months later, they will send the same query to Equifax to see if the credit rating hasn't changed. These sensitive information are indexes to external databases (but Cash_Ur_check doesn't directly connect to these other databases). Cash_Ur_check doesn't need to use these data as indexes. Cash_Ur_check can use first/middle/last name of person as an index, or attribute some random number to the person, or something else, they should not use the SIN to identify a person. They should not do searches on SIN to find a person given his SIN. Sure, but Equifax should. No, they shouldn't! If you think they should, you are missinformed. At least in Canada, the Privacy Act protects the SIN, Equifax cannot demand it. See for example http://www.privcom.gc.ca/fs-fi/02_05_d_02_e.asp and http://www.guardmycreditfile.org/index.php/content/view/244/139/ which says the following: Even credit reporting companies cant demand a SIN to generate a credit report. Trans Union Canada and Equifax Canada both have the ability to generate such reports without a SIN. If you ask these same companies to generate a credit report in the United States, they both require a Social Security Number. And if Equifax Canada can generate reports without a SIN, I don't see why Equifax in any other country couldn't. Of course, they like to have the SIN, since it makes things more convenient, but they don't really need it! That is the problem in most cases. --Anton - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
[EMAIL PROTECTED] wrote: Ben Laurie wrote [EMAIL PROTECTED] wrote: Example: Cash_Ur_check is in the business of cashing checks. To cash a check, they ask you for sensitive information like SIN, bank account number, drivers licence number, etc. They use the information to query Equifax or the like to see if the person has a good credit rating, if the rating is o.k. they cash the check. They keep all the information in the database, because if the client comes back 2 months later, they will send the same query to Equifax to see if the credit rating hasn't changed. These sensitive information are indexes to external databases (but Cash_Ur_check doesn't directly connect to these other databases). Cash_Ur_check doesn't need to use these data as indexes. Cash_Ur_check can use first/middle/last name of person as an index, or attribute some random number to the person, or something else, they should not use the SIN to identify a person. They should not do searches on SIN to find a person given his SIN. Sure, but Equifax should. No, they shouldn't! If you think they should, you are missinformed. At least in Canada, the Privacy Act protects the SIN, Equifax cannot demand it. I am just reading what you've written: To cash a check, they ask you for sensitive information like SIN, bank account number, drivers licence number, etc. They use the information to query Equifax or the like -- ApacheCon Europe http://www.apachecon.com/ http://www.apache-ssl.org/ben.html http://www.thebunker.net/ There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit. - Robert Woodruff - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
On Fri, Jun 10, 2005 at 01:11:45PM -0400, [EMAIL PROTECTED] wrote: | Ben Laurie wrote | Sure, but Equifax should. | | No, they shouldn't! If you think they should, you are missinformed. At | least in Canada, the Privacy Act protects the SIN, Equifax cannot demand | it. | See for example | http://www.privcom.gc.ca/fs-fi/02_05_d_02_e.asp | and | http://www.guardmycreditfile.org/index.php/content/view/244/139/ | which says the following: | Even credit reporting companies cant demand a SIN to generate a credit | report. Trans Union Canada and Equifax Canada both have the ability to | generate such reports without a SIN. If you ask these same companies to | generate a credit report in the United States, they both require a Social | Security Number. | | And if Equifax Canada can generate reports without a SIN, I don't see why | Equifax in any other country couldn't. Of course, they like to have the | SIN, since it makes things more convenient, but they don't really need it! | That is the problem in most cases. Actually, there's a difference between theory and practice here. When I signed up for a mobile phone, they demanded a SIN, or would put me on the sucker plan. When I complained to the Quebec privacy commissioner, they told me that that was OK. There are so many examples of this sort of thing that I gave up sending complaint letters. Then you look at CIBC, and the lack of fines... Adam - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
[EMAIL PROTECTED] wrote: Ben Laurie wrote [EMAIL PROTECTED] wrote: Example: Cash_Ur_check is in the business of cashing checks. To cash a check, they ask you for sensitive information like SIN, bank account number, drivers licence number, etc. They use the information to query Equifax or the like to see if the person has a good credit rating, if the rating is o.k. they cash the check. They keep all the information in the database, because if the client comes back 2 months later, they will send the same query to Equifax to see if the credit rating hasn't changed. These sensitive information are indexes to external databases (but Cash_Ur_check doesn't directly connect to these other databases). Cash_Ur_check doesn't need to use these data as indexes. Cash_Ur_check can use first/middle/last name of person as an index, or attribute some random number to the person, or something else, they should not use the SIN to identify a person. They should not do searches on SIN to find a person given his SIN. Sure, but Equifax should. No, they shouldn't! If you think they should, you are missinformed. At least in Canada, the Privacy Act protects the SIN, Equifax cannot demand it. I am just reading what you've written: To cash a check, they ask you for sensitive information like SIN, bank account number, drivers licence number, etc. They use the information to query Equifax or the like They'll ask for it, but you don't have to give it. They can collect it, but they don't have to do searches on it. It's the typical ask for SIN if the user gives it use it (as in Adam Shostack's example with cell phone), but if they don't then ask for 2 other identity cards. In most cases, I don't have to give my SIN, but almost everybody asks for it. Equifax will always ask for the SIN but they don't have the right to demand it. http://www.piac.ca/newpage91.htm Equifax suggests that to prevent these inaccuracies, consumers should always give their full name and SIN number on application forms (this facilitates updating of files and prevents confusion of two files). However, this solution to the problem does not take into account that consumers have a valid interest in protecting their privacy with respect to their SIN. The problem is with forms that make it look like you have to give your SIN, when in fact the law says you don't have to. Providing other identification can be troublesome, so allot of people just end up giving their SIN. --Anton - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
RE: encrypted tapes (was Re: Papers about Algorithm hiding ?)
Jerrold Leichter [EMAIL PROTECTED] writes: They also sold a full solution for encrypted Ethernet - KDC, encrypting Ethernet adapters, associated software. None of this stuff went anywhere. People just weren't interested. That wasn't quite the case for the Ethernet encryption. What happened there was that they had a complete product ready to ship and quite a bit of interest when it was killed by marketing. The problem was that Ethernet at the time wasn't the forgone conclusion it is now, it was just one of a number of potential candidates for the foregone-conclusion role. By shipping an encrypting Ethernet adapter, marketing felt that DEC were saying that standard Ethernet wasn't safe. In contrast token ring didn't have an encryption adapter, so obviously token ring must be secure by default, whereas Ethernet clearly wasn't. As a result, the encryption adapter was never shipped. Strategy is not letting the enemy know you're out of bullets by continuing to fire. Peter. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
On Wednesday 08 June 2005 21:20, [EMAIL PROTECTED] wrote: Yes, encrypting indexed columns for example is a problem. But if you limit yourself to encrypting sensitive information (I'm talking about stuff like SIN, bank account numbers, data that serves as an index to external databases and are sensitive with respect to identity theft), these sensitive information should not be the bases of searches. If they are not he basis of searches, there will be no performance problems related to encrypting them. I can name at least one obvious case where sensitive data -- namely credit card numbers -- is in fact something you want to search on: credit card billing companies like CCbill and iBill. Without the ability to search by CC#, customers are pretty screwed. That said, I will never buy the only encrypt sensitive data argument. In my experience, you *always* end up leaking something that way. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
On Wed, 8 Jun 2005, David Wagner wrote: [...] That said, I don't see how adding an extra login page to click on helps. If the front page is unencrypted, then a spoofed version of that page can send you to the wrong place. Sure, if users were to check SSL certificates extremely carefully, they might be able to detect the funny business -- but we know that users don't do this in practice. Dan Bernstein has been warning of this risk for many years. http://cr.yp.to/djbdns/bugtraq/[EMAIL PROTECTED] http://cr.yp.to/dnscache/bugtraq/[EMAIL PROTECTED] As far as I can tell, if the front page is unencrypted, and if the attacker can mount DNS cache poisoning, pharming, or other web spoofing attacks -- then you're hosed. Did I get something wrong? Well, yes. TLS guarantees that you're talking to the website listed in the location bar. Knowing what domain you *wanted* is up to you, and Dan handles that by suggesting that perhaps you have a paper brochure from the bank which lists their domain. So, it's fine to have http://amex.com link to https://amex.com (or whatever.com) for forms requesting anything sensitive as long as amex.com (or whatever.com) is what's printed in the brochure. As Dan points out, examination of the certificate is generally pointless as long as it's signed by a trusted CA, since the attacker can get a perfectly valid cert for hackers-r-us.com anyway. The big question is just whether the domain asking for your account info corresponds with the organization you trust with it. Of course, brochures aren't exactly hard to spoof (cf. Verisign's fraudulent domain renewal postcards). And then there are the dozens of CAs your browser accepts, the CA staff who issue microsoft.com certs to random passersby, international domain names that look identical to, er, national ones. All those gotchas apply even in the correct implementation outlined by Dan. -J - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
[EMAIL PROTECTED] wrote: | Oracle, for example, provides encryption functions, but the real problem | is the key handling (how to make sure the DBA can't get the key, cannot | call functions that decrypt the data, key not copied with the backup, | etc.). | There are several solutions for the key management, but the vendors should | start offering them. I would argue that the real problem is that encryption slows large searches (is percieved to slow large searches, anyway.) Adam Yes, encrypting indexed columns for example is a problem. But if you limit yourself to encrypting sensitive information (I'm talking about stuff like SIN, bank account numbers, data that serves as an index to external databases and are sensitive with respect to identity theft), these sensitive information should not be the bases of searches. If they are not he basis of searches, there will be no performance problems related to encrypting them. If they are indexes to external databases, then they are the basis of searches in those databases, by definition. So my answer to people that have the perception you mentioned is that if you want to encrypt sensitive information and that would cause performance problems, then there are problems with your data architecture privacy wise (you should re-structure your data, use it differently, etc.). Not a very satisfactory answer. -- http://www.apache-ssl.org/ben.html http://www.thebunker.net/ There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit. - Robert Woodruff - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
From: Charles M. Hannum [EMAIL PROTECTED] I can name at least one obvious case where sensitive data -- namely credit card numbers -- is in fact something you want to search on: credit card billing companies like CCbill and iBill. Without the ability to search by CC#, customers are pretty screwed. Is there a good reason for not searching by the hash of a CC# ? http://www.wayner.org/books/td/ http://www.unixwiz.net/techtips/secure-cc.html I think the author is planning further work on this site and would be happy to receive constructive comments. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
On Thursday 09 June 2005 17:37, Charles M. Hannum wrote: If we assume that the last 4 digits have been exposed somewhere -- and they usually are -- then this gives you at most 38 bits -- i.e. 2^38 hashes to test -- to search (even a couple less if you know a priori which *brand* of card it is). How long do you suppose this would take? On reconsideration, given the presence of the check digit, I think you have at most 2^34 tests (or 2^32 if you know the brand of card). And this assumes there aren't additional limitations on the card numbering scheme, which there always are. I guess you could use a keyed hash. Remember, though, you can't use random padding if this is going to be searchable with a database index, so the amount of entropy you're putting in is pretty limited. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
On Wednesday 08 June 2005 21:20, [EMAIL PROTECTED] wrote: Yes, encrypting indexed columns for example is a problem. But if you limit yourself to encrypting sensitive information (I'm talking about stuff like SIN, bank account numbers, data that serves as an index to external databases and are sensitive with respect to identity theft), these sensitive information should not be the bases of searches. If they are not he basis of searches, there will be no performance problems related to encrypting them. I can name at least one obvious case where sensitive data -- namely credit card numbers -- is in fact something you want to search on: credit card billing companies like CCbill and iBill. Without the ability to search by CC#, customers are pretty screwed. That said, I will never buy the only encrypt sensitive data argument. In my experience, you *always* end up leaking something that way. There are exceptions, I grant you that, but my hypothesis is that in most cases you can do without indexing on the sensitive data you have. Encrypting everything in your database, I say that will never work. If you do that, then you will have performance trouble, and nobody want's that. You can do stuff like encrypt everything at the OS level, but that doesn't help protect database backups and it doesn't prevent your DBA to look at data he's not supposed to. If you encrypt everthing at the DBMS level or at the application (client or middleware) level, than you cannot encrypt indexed data. --Anton --Anton - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
[EMAIL PROTECTED] wrote: | Oracle, for example, provides encryption functions, but the real problem | is the key handling (how to make sure the DBA can't get the key, cannot | call functions that decrypt the data, key not copied with the backup, | etc.). | There are several solutions for the key management, but the vendors should | start offering them. I would argue that the real problem is that encryption slows large searches (is percieved to slow large searches, anyway.) Adam Yes, encrypting indexed columns for example is a problem. But if you limit yourself to encrypting sensitive information (I'm talking about stuff like SIN, bank account numbers, data that serves as an index to external databases and are sensitive with respect to identity theft), these sensitive information should not be the bases of searches. If they are not he basis of searches, there will be no performance problems related to encrypting them. If they are indexes to external databases, then they are the basis of searches in those databases, by definition. My terminology might have been misleading. By indexes to external databases, I don't mean that the application that uses the database actually talks to the external databases (it doesn't use the info as a key to that external database) - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
[EMAIL PROTECTED] writes: I saw allot of requirements by security auditors that looked pretty silly. Must use 128-bit RSA encryption has to be the all-time favourite. One I saw recently was a requirement for using X9.17 key management... in SSL. Peter. One of my favourites was that PINs had to be hashed (these were PINs for authentication in a proprietary application/system. The justification (given by the auditor) was that people who had access to the database, should not be able to see the PINs in clear. These where 4 digit PINs. So the developers just SHA-oned the PINs. Later on, the developers had to export the PINs into another application, that had its own way to protect the PINs, so they launched a brut force attack on all of the PINs, of course this was easy because the input space was very small and the hash function did not involve any secret key, no salt, no iterations... Talk about protection! --Anton - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
Perry E. Metzger wrote: Have a look, for example, at http://www.americanexpress.com/ which encourages users to type in their credentials, in the clear, into a form that came from lord knows where and sends the information lord knows where. Spoof the site, and who would notice? Every company should be telling its users never to type in their credentials on a web page downloaded in the clear, but American Express and lots of other companies train their users to get raped, and why do they do it? Not because they made some high level decision to screw their users. Not because they can't afford to do things right. It happens because some idiot web designer thought it was a nice look, and their security people are too ignorant or too powerless to stop it, that's why. Why is it bad for the page to be downloaded clear? What matters is the destination is encrypted, surely? Which, as it happens, it is on the above site. -- http://www.apache-ssl.org/ben.html http://www.thebunker.net/ There is no limit to what a man can do or how far he can go if he doesn't mind who gets the credit. - Robert Woodruff - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
RE: encrypted tapes (was Re: Papers about Algorithm hiding ?)
Steven M. Bellovin wrote: The bigger issue, though, is more subtle: keeping track of the keys is non-trivial. These need to be backed up, too, and kept separate from (but synchronized with) the tapes. Worse yet, they need to be kept secure. That may mean storing the keys with a different escrow company. A loss of either piece,the tape or the key, renders the backup useless. This is correct. It is not that nobody ever thought of encrypting tapes, it is that there has been no uptake on the idea because the management overhead costs outweighed the perceived benefit. The big vendors didn't bother offering it because they didn't think they could make money, and the start-ups who have been trying to fill the gap found the market to be small. Now it is becoming clear that the perceived benefit has been underestimated. There are a number of small companies making products that can encrypt data in a storage infrastructure, including tape backups (full disclosure: I work for one of those companies). The solutions all involve appliances priced in the tens of thousands. The costs come not from encryption (how much does an FPGA cost these days?), but from solving the problems you listed, plus some others you didn't. Now that the benefit of storage encryption is clearer, tape vendors (StorageTek, HP, IBM, etc) are almost certainly looking at adding encryption capability into their offerings. There is an IEEE working group developing interoperability standards for storage encryption, including tape: http://www.siswg.org And in case anyone is really interested in this subject, Networking Computing magazine did a round-up of all the storage infrastructure security solutions currently on the market: http://www.networkcomputing.com/showitem.jhtml?docid=1607f2 Ken - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
Perry wrote: In case you think the answer is regulation, by the way, let me note that most of the regulatory pressure I've seen on security policy results in people finding extremely well documented ways to do exactly what the regulators ask, to no actual effect. This is generally because the regulators are almost uniformly as dumb or dumber than the people they regulate. One thing that irritates me is that most security audits (that verify compliance with regulations) are done by accountants. No disrespect for accountants here, they are smart people, but most of them lack the security knowledge needed to really help with the security posture of a company, and often they don't work with a security expert. I saw allot of requirements by security auditors that looked pretty silly. I believe a mix of accountants with security experts should be used for security audits --Anton - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
On Wed, Jun 08, 2005 at 01:33:45PM -0400, [EMAIL PROTECTED] wrote: | | Ken Buchanan wrote: | There are a number of small companies making products that can encrypt | data in a storage infrastructure, including tape backups (full disclosure: | I work for one of those companies). The solutions all involve appliances | priced in the tens of thousands. The costs come not from encryption (how | much does an FPGA cost these days?), but from solving the problems you | listed, plus some others you didn't. | | Now that the benefit of storage encryption is clearer, tape vendors | (StorageTek, HP, IBM, etc) are almost certainly looking at adding | encryption capability into their offerings. | | Another area where I predict vendors will (should) offer built in | solutions is with database encryption. Allot of laws require need-to-know | based access control, and with DBA's being able to see all entries that is | a problem. Also backups of db data can be a risk. | Oracle, for example, provides encryption functions, but the real problem | is the key handling (how to make sure the DBA can't get the key, cannot | call functions that decrypt the data, key not copied with the backup, | etc.). | There are several solutions for the key management, but the vendors should | start offering them. I would argue that the real problem is that encryption slows large searches (is percieved to slow large searches, anyway.) Adam - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
2) The cost in question is so small as to be unmeasurable. Yes, because key management is easy or free. Also, reliability of encrypted backups is problematic: CBC modes render a single fault destructive to the entire dataset. Counter mode is sufficiently new that it's not supported by existing code. --Dan - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
| Oracle, for example, provides encryption functions, but the real problem | is the key handling (how to make sure the DBA can't get the key, cannot | call functions that decrypt the data, key not copied with the backup, | etc.). | There are several solutions for the key management, but the vendors should | start offering them. I would argue that the real problem is that encryption slows large searches (is percieved to slow large searches, anyway.) Adam Yes, encrypting indexed columns for example is a problem. But if you limit yourself to encrypting sensitive information (I'm talking about stuff like SIN, bank account numbers, data that serves as an index to external databases and are sensitive with respect to identity theft), these sensitive information should not be the bases of searches. If they are not he basis of searches, there will be no performance problems related to encrypting them. So my answer to people that have the perception you mentioned is that if you want to encrypt sensitive information and that would cause performance problems, then there are problems with your data architecture privacy wise (you should re-structure your data, use it differently, etc.). --Anton - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
encrypted tapes (was Re: Papers about Algorithm hiding ?)
Ben Laurie writes: Why is it bad for the page to be downloaded clear? What matters is the destination is encrypted, surely? Because the page you downloaded in the clear contains the https: URL in the post method. How do you know that this is the right URL? If you got the page in the clear, you don't. An attacker who can provide a spoofed page (by DNS cache poisoning, pharming, MITM attacks, or any other method) could substitute a post URL that sends your sensitive data to hackers-r-us.com. That said, I don't see how adding an extra login page to click on helps. If the front page is unencrypted, then a spoofed version of that page can send you to the wrong place. Sure, if users were to check SSL certificates extremely carefully, they might be able to detect the funny business -- but we know that users don't do this in practice. Dan Bernstein has been warning of this risk for many years. http://cr.yp.to/djbdns/bugtraq/[EMAIL PROTECTED] http://cr.yp.to/dnscache/bugtraq/[EMAIL PROTECTED] As far as I can tell, if the front page is unencrypted, and if the attacker can mount DNS cache poisoning, pharming, or other web spoofing attacks -- then you're hosed. Did I get something wrong? - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Papers about Algorithm hiding ?
From: Ian G [EMAIL PROTECTED] Sent: Jun 7, 2005 7:43 AM To: John Kelsey [EMAIL PROTECTED] Cc: Steve Furlong [EMAIL PROTECTED], cryptography@metzdowd.com Subject: Re: Papers about Algorithm hiding ? [My comment was that better crypto would never have prevented the Choicepoint data leakage. --JMK] Sure it would. The reason they are not using the tools is because they are too hard to use. If the tools were so easy to use that it was harder to not use them, then they'd be used. Consider Citigroup posted today by Bob. They didn't encrypt the tapes because the tools don't work easily enough for them. So, this argument might make sense for some small business, but Citigroup uses a *lot* of advanced technology in lots of areas, right? I agree crypto programs could be made simpler, but this is really not rocket science. Here's my guess: encrypting the data would have required that someone make a policy decision that the data be encrypted, and would have required some coordination with the credit agency that was receiving the tapes. After that, there would have been some implementation costs, but not all *that* many costs. Someone has to think through key management for the tapes, and that's potentially a pain, but it's not intractible. Is this really more complicated than, say, maintaining security on their publically accessible servers, or on their internal network? ... The other way of looking at Choicepoint - change the incentives - is a disaster. It will make for a compliance trap. Compliance *may* protect the data or it may have completely the opposite effect, the situation with 'unintended consequences' in such a case is likely to be completely unpredictable. The only thing we can guarantee is that costs will go up. Well, Choicepoint is a bit different, right? I mean, as I understand it the big disclosure happened because they sold peoples' data to criminals, but they were in the business of selling peoples' data. They just intended to sell it only to people of good intention, as far as I can tell. (Perhaps they should have demanded X.509 certificates from the businesses buying the data and checked the evil bit.) I just can't see how cryptography could have helped prevent that attack, other than by making the data that Choicepoint depends on harder to get in the first place. It's much cheaper and much more secure to simply improve the tools. But this does no good whatsoever if there's not some reason for the people holding the data to use those tools. Everyone with a network presence and any kind of high profile does, in fact, use moderately complicated computer security tools like routers, firewalls, VPNs, virus scanners, and spyware detectors. Everyone has to deal with keeping their boxes up to date on patches. However imperfectly, it seems like Citigroup and Choicepoint and the rest can actually do those things. So when you excuse their failures to secure customer data with the tools aren't there, this sounds absolutely implausible to me. I'm not crazy about a HIPAA-style mandate for encryption and shredders either, but we have this basic problem: a. It's basically easy to buy or find some amount of data about many people. b. It's basically easy to use that amount of data to get credit in their name. I suspect a better solution than trying to regulate data brokers is to make it more expensive to give credit to Alice under Bob's name. The thing that imposes the cost on me isn't when someone finds my SSN, it's when someone takes out a bunch of loans which I'm then expected to pay back. Then it becomes my problem to resolve the disputes created by the lender's desire to extend credit at minimal cost. (The lender also loses money, of course. But much of the cost is shifted to the identity theft victim.) iang --John Kelsey - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Papers about Algorithm hiding ?
On Tuesday 07 June 2005 14:52, John Kelsey wrote: From: Ian G [EMAIL PROTECTED] Sent: Jun 7, 2005 7:43 AM To: John Kelsey [EMAIL PROTECTED] Cc: Steve Furlong [EMAIL PROTECTED], cryptography@metzdowd.com Subject: Re: Papers about Algorithm hiding ? [My comment was that better crypto would never have prevented the Choicepoint data leakage. --JMK] OK, yes, you are right, we are talking about two different things. The difficulty here is that there is what we might call the Choicepoint syndrome and then there is the specific facts about the actual Choicepoint heist. When I say Choicepoint I mean the former, and the great long list of similar failures as posted last week. I.e., it is a syndrome that might be characterised as companies are not protecting data or in other words the threat is on the node not the wire. Whereas in the specific Choicepoint heist, there is the precise issue that they are selling their data to someone. That's much more complex, and crypto won't change that issue, easily. Sure it would. The reason they are not using the tools is because they are too hard to use. If the tools were so easy to use that it was harder to not use them, then they'd be used. Consider Citigroup posted today by Bob. They didn't encrypt the tapes because the tools don't work easily enough for them. So, this argument might make sense for some small business, but Citigroup uses a *lot* of advanced technology in lots of areas, right? I agree crypto programs could be made simpler, but this is really not rocket science. Here's my guess: encrypting the data would have required that someone make a policy decision that the data be encrypted, and would have required some coordination with the credit agency that was receiving the tapes. After that, there would have been some implementation costs, but not all *that* many costs. Someone has to think through key management for the tapes, and that's potentially a pain, but it's not intractible. Is this really more complicated than, say, maintaining security on their publically accessible servers, or on their internal network? No it's not rocket science - it's economic science. It makes no difference in whether the business is small or large - it is simply a question of costs. If it costs money to do it then it has to deliver a reward. In the case of the backup tapes there was no reward to be enjoyed. So they could never justify encrypting them if it were to cost any money. Now, in an unusual exception to the rule that laws cause costs without delivering useful rewards, the California law SB changed all that by adding a new cost: disclosure. (Considering that banks probably lose a set of backups each every year and have been doing so since whenever, it's not the cost of the tapes or the potential for ID theft that we care about...) Now consider what happens when we change the cost structure of crypto such that it is easier to do it than not. This is a *hypothetical* discussion of course. Take tar(1) and change it such that every archive is created as an encrypted archive to many public keys. Remove the mode where it puts the data in the clear. Then encrypt to a big set of public keys such that anyone who can remotely want the data can decrypt it (this covers the biggest headache which is when you want the data it is no longer readable). So, now it becomes trivial to make an encrypted backup. In fact, it is harder to make an unencrypted backup. What are companies going to do? Encrypt, of course. Because it costs to do anything else. The other way of looking at Choicepoint - change the incentives - is a disaster. It will make for a compliance trap. Compliance *may* protect the data or it may have completely the opposite effect, the situation with 'unintended consequences' in such a case is likely to be completely unpredictable. The only thing we can guarantee is that costs will go up. Well, Choicepoint is a bit different, right? I mean, as I understand it the big disclosure happened because they sold peoples' data to criminals, but they were in the business of selling peoples' data. They just intended to sell it only to people of good intention, as far as I can tell. (Perhaps they should have demanded X.509 certificates from the businesses buying the data and checked the evil bit.) I just can't see how cryptography could have helped prevent that attack, other than by making the data that Choicepoint depends on harder to get in the first place. Yes, you are right, I was thinking Choicepoint syndrome here. In order to address Choicepoint-actual with crypto we'd have to look at Rights systems: nyms, caps and Brands, or address it at the business level. It's much cheaper and much more secure to simply improve the tools. But this does no good whatsoever if there's not some reason for the people holding the data to use those tools. Yes, that's why I'm saying that the tools should actually make
Re: Papers about Algorithm hiding ?
On Tue, Jun 07, 2005 at 05:41:12PM +0100, Ian G wrote: | | The difficulty here is that there is what we might call | the Choicepoint syndrome and then there is the | specific facts about the actual Choicepoint heist. | When I say Choicepoint I mean the former, and the | great long list of similar failures as posted last week. Poor form there. | No it's not rocket science - it's economic science. | It makes no difference in whether the business is | small or large - it is simply a question of costs. If | it costs money to do it then it has to deliver a | reward. | | In the case of the backup tapes there was no reward | to be enjoyed. So they could never justify encrypting | them if it were to cost any money. Now, in an unusual Actually, that's not true. Over 10 years ago, I wrote a small script that took data very much like this, encrypted it, verified the output looked like PGP encrypted data, and copied it to a public ftp site so that a partner could pick it up. That saved a lot over tape, and reduced manual steps which introduced errors. Adam - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
In message [EMAIL PROTECTED], Perry E. Metzger writes: The truth is, the likely reason no one encrypted the data on the tapes in transit was because no one thought to do it, or they were too lazy to bother to make even the simplest effort, or both. I don't completely agree. While I suspect that laziness or lack of thought are the primary problems, there are some real costs. The minor one is compression: most modern tape drives compress the data before writing, and you can't compress encrypted data. That means they'd need to compress in software before writing to the tape; that chews up CPU time that they may not have to spare on the machines in question. (Remember that we're talking about massive amounts of data here.) The bigger issue, though, is more subtle: keeping track of the keys is non-trivial. These need to be backed up, too, and kept separate from (but synchronized with) the tapes. Worse yet, they need to be kept secure. That may mean storing the keys with a different escrow company. A loss of either piece,the tape or the key, renders the backup useless. Backups are not very reliable to start with. Too few companies do regular checks on the adequacy or quality of their backups. Most companies feel they can't afford lowering the reliability even further. ... The only thing that will fix this having enough people get so badly burned that CEOs start taking heads when people do dumb things. I imagine it can't be too many more years before that becomes the case. Bingo. Especially the CEO's head -- or the CFO's head, or the general counsel's -- for some of the mistakes we've seen. But there's no one cause. For those who subscribe to the Wall Street Journal online, see http://online.wsj.com/documents/info-idtheft0504.html?mod=technology_main_promo_left for a chart of recent failures to protect identity data. Of the 10 failures for which a cause is listed, though, 4 were loss of tapes in transit. (One was a shipment of tapes to a credit bureau.) 2 involved hacking, one was an inside job, one was a stolen laptop, and 2 were fraudulent use of logins and passwords. --Steven M. Bellovin, http://www.cs.columbia.edu/~smb - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
On Tue, Jun 07, 2005 at 07:48:22PM -0400, Perry E. Metzger wrote: It happens because some idiot web designer thought it was a nice look, and their security people are too ignorant or too powerless to stop it, that's why. It has nothing to do with cost. The largest non-bank card issuer in the world can pay for the fifteen minutes of time it would take to fix it by putting the login on a separate SSL protected page. It has nothing to do with ease of use or tools that default safe. The problem is that they don't know there is anything to fix at a level of the firm that is capable of taking the decision to fix it. It may well be that, rather than the fault of the web designer, an explicit business requirement was presented to do this, because of perceived ease of use for the customer... and then the lack of knowing any better to kill the idea before it takes hold. At least, that's how it's happened in several places I've been involved, and it took more than a little effort to make them understand why it was a bad idea. Thankfully, they were paying for my time and advice, and *also* had the sense to listen to it when given - the two don't always go together - but in this sense security did cost them something. The customer ease-of-use argument is quite easy to see - and also quite easy to provide, if they want to, by putting the normal company homepage that contains the form on SSL too. I've had conversations about the cost of doing that with knowledgable web designers (largely centering on image caching concerns), and really, it isn't quite free, even if the costs come from unreasonable and annoying places. Those costs can have returns, even non-risk ones like being better able to track users' browsing patterns and site navigation, too - but just by virtue of having to have the conversation, its no longer free, especially if people bring organisational politics to the table. Security these days is usually bad not because good security is expensive, or because it is particularly hard. These are the things that make the difference between middling-fair and somewhat-decent security (let alone good security, which requires many other things to be Done Right, more operational than technical). The irony is that bad IT security (just like any other bad IT) is expensive, often much more expensive - even without considering the potential costs involved if the risks are realised. It is bad because even people at giant multinational corporations with enough budget to spare are too dumb to implement it. Worse than that: people at the giant multinational corporations who provide the outsourced IT services to those other corporations - and who sell their services based on 'economies of scale' and 'industry expertise' and 'best practice', and who are thus charged with the responsibility of knowing better - are too dumb to implement it. And then they're too dumb to implement it at other customer sites even when that one rare customer comes along who knows better (or at least knows to ask for independent outside help), and has fought hard to convinve their outsource provider of the need and economic sense of not being dumb on their behalf. Most organisations just let them get away with it, and think they're getting a good deal, while the very basis on which that deal was sold is defeated. If it weren't for all the other people that get hurt by the schrapnel, it would be very hard to continue trying to help people who seem to like walking around with bullet holes in their shoes. -- Dan. pgpj1TA56flkt.pgp Description: PGP signature
Re: encrypted tapes (was Re: Papers about Algorithm hiding ?)
Steven M. Bellovin wrote: The bigger issue, though, is more subtle: keeping track of the keys is non-trivial. These need to be backed up, too, and kept separate from (but synchronized with) the tapes. Worse yet, they need to be kept secure. That may mean storing the keys with a different escrow company. A loss of either piece,the tape or the key, renders the backup useless. Basically, expensive or not, security is very hard to get right. When you look at Choicepoint, Bank of America, and Citigroup (not to mention universities and smaller businesses) they have little to no incentive to keep your personal data secure. YOU bear the cost of data compromise, not them. The worst they get is some bad publicity and only if it affects CA residents, otherwise it can be kept quiet. The threat of bad publicity does not mean much when next week your compromise due to bad security will be forgotten as the media switches to the next one. As it stands today, the cost/benefit analysis easily directs them away from taking strong measures to protect customer's financial data. Doing so is time consuming, opens up potential for problems, and gets them next to nothing in return. -- Mark Allen Earnest Lead Systems Programmer Emerging Technologies The Pennsylvania State University Lt Commander Centre County Sheriff's Office Search and Rescue KB3LYB smime.p7s Description: S/MIME Cryptographic Signature
Re: Papers about Algorithm hiding ?
From: Ian G [EMAIL PROTECTED] Sent: Jun 4, 2005 6:43 AM To: Steve Furlong [EMAIL PROTECTED] Cc: cryptography@metzdowd.com Subject: Re: Papers about Algorithm hiding ? GPG is an application that could be delivered by default in all free OSs. BSD is more or less installed automatically with SSH installed. Linux machines that are set up are also generally set up with SSH. I think you need one more step here to get the protective coloration effect you'd like, where encrypted files aren't automatic evidence of wrongdoing: During installation, generate 50 or so random passwords with too much entropy to feasibly guess (easy to do when no user need ever remember them), and encrypt some reasonable-length files full of binary zeros with them. The number of randomly-generated files needs to be randomized, naturally, and probably should follow some kind of distribution with a big tail to the right, so that it's not that uncommon for a random install to put several hundred encrypted files on the drive. The value of this is that an attacker now sees encrypted files on every machine, most of which nobody on Earth can decrypt. If this is normal, then it's not evidence. (There are probably a bunch of issues here with putting plausible tracks in the logs, datestamps on the files, etc. But it seems like something like this could work) ... Certainly using another app is fine. What would be more relevant to the direct issue is that it becomes routine to encrypt and to have encryption installed. See the recent threads on where all the data is being lost - user data is being lost simply because the companies don't protect it. Why aren't they protecting it? Because there are no easy tools that are built in to automatically and easily protect it. Huh? There have been effective tools for protecting data from disclosure for a long time, though it's not clear what good they'd do for a company whose whole business was just selling access to that data for a fee. I'll bet the Choicepoints of the world are pretty careful protecting, say, their payroll and HR records from disclosure. It's just *your* data they don't mind giving out to random criminals. No amount of crypto could have helped this. iang --John Kelsey - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Papers about Algorithm hiding ?
At 01:14 PM 6/3/2005, [EMAIL PROTECTED] wrote: I think we are already in a state where practically everybody that has a computer has crypto available, and it's not difficult to use it! Of course they have it - the problem is having crypto in a way that's not suspicious, and suspicious is highly dependent on your threat model. For instance, Microsoft Word has crypto - it's lousy crypto, which isn't directly relevant here, but it's a utility that people view as normal, while PGP is inherently suspicious-looking. No reason that OpenOffice couldn't have crypto that's actually reasonable quality. The rename the binaries strategy is probably more reliable than cyphersaber etc. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Papers about Algorithm hiding ?
On Thursday 02 June 2005 13:50, Steve Furlong wrote: On 5/31/05, Ian G [EMAIL PROTECTED] wrote: I don't agree with your conclusion that hiding algorithms is a requirement. I think there is a much better direction: spread more algorithms. If everyone is using crypto then how can that be relevant to the case? This is so, in the ideal. But if everyone would only... never seems to work out in practice. Better to rely on what you can on your own or with a small group. The number of people who are involved is actually quite small if you think it through. It's more a shift in attitude that is the barrier, not a large number of people who have to be sold. GPG is an application that could be delivered by default in all free OSs. BSD is more or less installed automatically with SSH installed. Linux machines that are set up are also generally set up with SSH. From there it isn't a large step conceptually to install GPG in the base installs. Start with the BSDs (because they understand security) and Linux (because they understand cool). It's also not a large step to add a special hook into SSH and browsers to add a simple file encryption utility. Just like OpenPGP's secret key mode. It doesn't have to be good, it just has to be there. A lot of machines have OpenSSL in them (this is how we get easy access to SHA1). Can we add a simple file encrypt to that? Once all the Unixen have these, the next step is to encourage a little usage... All you need to do is have one person that you communicate with like your brother or sister for the fun of doing some crypto chat, and it now becomes a regular *non-relevant* issue. All we need to do is to encrypt and protect one file and encryption becomes easy. In response to Hadmut's question, for instance, I'd hide the crypto app by renaming the executable. This wouldn't work for a complex app like PGP Suite but would suffice for a simple app. Rename the encrypted files as well and you're fairly safe. (I've consulted with firms that do disk drive analysis. From what I've seen, unless the application name or the data file extensions are in a known list, they won't be seen. But my work has been in the realm of civil suits, contract disputes, SEC claims, and the like; the investigators might be more thorough when trying to nail someone for kiddie porn.) Right. If they find any evidence of information hiding other than a boring OpenPGP install that is as common as crazy frog mp3s then that's what I'd call highly relevent evidence. That would make matters worse for the particular case at hand. Information hiding is real sexy. I wouldn't recommend it for anyone who isn't really sure of their situation, and is willing to understand that if he gets caught with it, he's dead. Or use another app which by the way has crypto. Winzip apparently has some implementation flaws (http://www.cse.ucsd.edu/users/tkohno/papers/WinZip/ ) but a quick google doesn't show anything but brute force and dictionary attacks against WinRar. Certainly using another app is fine. What would be more relevant to the direct issue is that it becomes routine to encrypt and to have encryption installed. See the recent threads on where all the data is being lost - user data is being lost simply because the companies don't protect it. Why aren't they protecting it? Because there are no easy tools that are built in to automatically and easily protect it. The picture here is becoming overwhelmingly clear - in order to protect users we should be employing as much crypto as we can openly, opportunistically, and easily. Anything that holds back from users protecting their data is a bad, and anything that moves them forward in protecting their data is a good. iang -- Advances in Financial Cryptography: https://www.financialcryptography.com/mt/archives/000458.html - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Papers about Algorithm hiding ?
On 6/3/05, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Another alternative is the cyphersaber type of thing, where you could just implement your crypto-code on the fly, as needed. Yes, I could, and have. Presumably you could. Ben Laurie probably could blindfolded with both hands tied behind his back. But Alice Philanderer, Bob Pedophile, Charlie Terrorist, and Generic Joe User can't. Your alternative is more practical than if everybody would xxx (sorry, Ian) but still not good enough. If only techies are able to protect themselves from the JBTs, then merely being a techie will be grounds for suspicion. (As well as throwing our non-programming brethren to the wolves.) The only realistic solutions are those which allow the concerned but non-technical user to take measures to protect himself against the perceived threat, without requiring major changes to human nature or to society. As it happens, I have really good test cases to refine my solutions: my extended family is a bunch of mountain hicks with internet access. They're not especially educated and certainly not technically adept, and are concerned about the gummint grabbing their computers or snooping their traffic. Once I've got an acceptable suite of tools and a training package put together, I'll post it somewhere. (Don't hold your collective breath; making a living takes most of my time.) Regards, SRF -- There are no bad teachers, only defective children. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Papers about Algorithm hiding ?
On 5/31/05, Ian G [EMAIL PROTECTED] wrote: I don't agree with your conclusion that hiding algorithms is a requirement. I think there is a much better direction: spread more algorithms. If everyone is using crypto then how can that be relevant to the case? This is so, in the ideal. But if everyone would only... never seems to work out in practice. Better to rely on what you can on your own or with a small group. In response to Hadmut's question, for instance, I'd hide the crypto app by renaming the executable. This wouldn't work for a complex app like PGP Suite but would suffice for a simple app. Rename the encrypted files as well and you're fairly safe. (I've consulted with firms that do disk drive analysis. From what I've seen, unless the application name or the data file extensions are in a known list, they won't be seen. But my work has been in the realm of civil suits, contract disputes, SEC claims, and the like; the investigators might be more thorough when trying to nail someone for kiddie porn.) Or use another app which by the way has crypto. Winzip apparently has some implementation flaws (http://www.cse.ucsd.edu/users/tkohno/papers/WinZip/ ) but a quick google doesn't show anything but brute force and dictionary attacks against WinRar. -- There are no bad teachers, only defective children. - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
RE: Papers about Algorithm hiding ?
Isn't this what Rivest's Chaffing and Winnowing is all about? http://theory.lcs.mit.edu/~rivest/chaffing.txt Cheers, Scott -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hadmut Danisch Sent: Thursday, May 26, 2005 5:51 PM To: cryptography@metzdowd.com Subject: Papers about Algorithm hiding ? Hi, you most probably have heard about the court case where the presence of encryption software on a computer was viewed as evidence of criminal intent. http://www.lawlibrary.state.mn.us/archive/ctappub/0505/opa040381-0503.ht m http://news.com.com/Minnesota+court+takes+dim+view+of+encryption/2100-10 30_3-5718978.html Plenty of research has been done about information hiding. But this special court case requires algorithm hiding as a kind of response. Do you know where to look for papers about this subject? What about designing an algorithm good for encryption which someone can not prove to be an encryption algorithm? regards Hadmut - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED] - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
RE: Papers about Algorithm hiding ?
-Original Message- Hadmut Danisch wrote: ... Plenty of research has been done about information hiding. But this special court case requires algorithm hiding as a kind of response. Do you know where to look for papers about this subject? ... Here is the list that you can start with: [1] Boaz Barak, Oded Goldreich, Russell Impagliazzo, Steven Rudich, Amit Sahai, Sali Vadhan, Ke Yang. On the (im)possibility of obfuscating programs. In Proceedings of CRYPTO 2001. [2] Benjamin Lynn, Manoj Prabhakaran, Amit Sahai. Positive Results and Techniques for Obfuscation. In Proceedings of Eurocrypt 2004. [3] Hoeteck Wee. On Obfuscating Point Functions. Computer Science Division University of California, Berkeley. Jan 2005 [4] Christian Collberg, Clark Thomborson. Watermarking, tamper-proofing and obfuscation - tools for software protection. IEEE Transactions on software engineering, vol.28, No.8, August 2002. [5] Christian Collberg, Clark Thomborson. Watermarking, tamper-proofing and obfuscation - tools for software protection. Technical Report TR00-03, The Department of Computer Science, University of Arizona, February 2000. [6] Christian Collberg, Clark Thomborson, Douglas Low. Breaking Abstractions and Unstructuring Data Structures. IEEE International Conference on Computer Languages, May 1998. [7] Christian Collberg, Clark Thoborson, Douglas Low. Manufacturing Cheap, Resilient, and Stealthy Opaque Constructs. Principles of Programming Languages 1998, POPL'98, January 1988. [8] Christian Collberg, Clark Thomborson, Douglas Low. A Taxonomy of Obfuscating Transformations. Technical Report 148, Department of Computer Science, The University of Auckland. July 1997. [9] Chenxi Wang, Jonathan Hill, John Knight, Jack Davidson. Protection of Software-based Survivability Mechanisms. International Conference of Dependable Systems and Networks. July 2001. [10] Chenxi Wang. A Security Architecture for Survivability Mechanisms. PhD Dissertation, Department of Computer Science, University of Virginia, October 2000. [11] Chenxi Wang, Jonathan Hill, John Knight, Jack Davidson. Software Tamper Resistance: Obstructing Static Analysis of Programs. Technical Report CS-2000-12, Department of Computer Science, University of Virginia. May 2000. [12] Cullen Linn, Saumya Debray. Obfuscation of Executable Code to Improve Resistance to Static Disassembly. ACM Conference on Computer and Communications Security (CCS 2003), October 2003, pp. 290-299 [13] Fritz Hohl. A Framework to Protect Mobile Agents by Using Reference States. Proceedings of the 20th International Conference on Distributed Computing Systems (ICDCS 2000), pp. 410-417, 2000. [14] Gregory Wroblewski. General Method of Program Code Obfuscation. PhD Dissertation, Wroclaw. 2002. [15] S. Chow, H. Johnson, P.C. van Oorschot, P Eisen. A White-Box DES implementation for DRM applications. In Proceedings of ACM CCS-9 Workshop DRM. 2002 [16] Matthias Jacom, Dan Boneh, Edard Feltin. Attacking an obfuscated cipher by injecting faults. In Proceedings of ACM CCS-9 Workshop DRM. 2002. [17] Yuval Ishai, Amit Sahai, David Wagner. Private Circuits: Securing Hardware against Probing Attacks. In Proceedings of CRYPTO 2003. [18] Markus Kuhn, Oliver Kommerling. Design Principles for Tamper-Resistant Smartcard Processors. USENIX Workshop on Smartcard Technology proceedings, Chicago, Illinois, USA, May 10-11, 1999. [19] Ross Anderson, Markus Kuhn. Tamper resistance - a Cautionary Note. The Second USENIX Workshop on Electronic Commerce Proceedings, Oakland , California, November 18-21 1996, pp 1-11. [20] Gael Hachez. A Comparative Study of Software Protection Tools Suited for E-Commerce with Contributions to Software Watermarking and Smart Cards. PhD thesis, Faculte des Sciences Appliquees Laboratoire de Microelectronique. Universite Catholique de Louvain. March 2003. [21] T.-C. Lin, M. Hsiang Hsu, F.-Y. Kuo, and P.-C. Sun. An Intention Model-based Study of Software Piracy. In 32nd Annual Hawaii International Conference on System Sciences (HICSS-32). IEEE Computer Society, January 1999. [22] Amit Sethi. Digital Rights Management and Code Obfuscation. Thesis in fulfillment of degree of Master of Mathematics. University of Waterloo, Ontario, Canada. 2003. [23] M. Kunin. Why do Software Manufactures Tolerate Piracy in Transition and Less Developed Countries? A theoretical model. Discussion Paper Series 2001-75, JEL classification: O34;L20. Center for Economic Research, Charles University and the Academy of Sciences, Czech Republic, October 2001. [24] Christian Collberg. SandMark Algorithms. January 28, 2003 [25] Christian Collberg, Ginger Myles, Michael Stepp. Cheating Cheating Detectors. Department Computer Science University of Arizona. Technical Report TR04-05. March 3, 2004 [26] James R. Gosler. Software Protection: Myth or Reality? Sandia National Laboratory. Advances in Cryptology - CRYPTO'85. 1985. [27] Kelly Heffner, Christian Collberg. The Obfuscation Executive.
Re: Papers about Algorithm hiding ?
HD What about designing an algorithm good for encryption which someone HD can not prove to be an encryption algorithm? Hmmm, but to do that one needs to have a good definition of 'encryption algorithm' and perhaps also some other apparently fundamental terms. But we have none, I am afraid ... at least it seems it is hard to give precise definition even of the cryptography alone (the old one relating that to 'secure communication over insecure channel' seems not to be consistent with quantum crypto...) Regards, Jozef - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Papers about Algorithm hiding ?
| Hi, | | you most probably have heard about the court case where the presence | of encryption software on a computer was viewed as evidence of | criminal intent. | | http://www.lawlibrary.state.mn.us/archive/ctappub/0505/opa040381-0503.htm | http://news.com.com/Minnesota+court+takes+dim+view+of+encryption/2100-1030_3-5718978.html | | | | Plenty of research has been done about information hiding. | But this special court case requires algorithm hiding as a kind of | response. Do you know where to look for papers about this subject? There was a paper published on this a while back. The question was posed as essentially: Can one produce a one-way trapdoor compiler? That is, just as an encryption algorithm takes plaintext and converts it to cryptotext, with the property that the inverse transformation is computationally intractable without the key, we want something that takes an algorithm and a key and produces a different but equivalent algorithm, such that asking some set of questions (like, perhaps, whether the output really *is* equivalent to the input) without the key is computationally intractable. The result of the paper was that no such compiler can exist. | What about designing an algorithm good for encryption which someone | can not prove to be an encryption algorithm? Can prove *any* algorithm is an encryption algorithm? If so, I think there are some big prizes coming your way. On a more general note: This court case is being blown out of proportion. Screwdrivers, hammers, and a variety of other implements are burglar's tools. If you are caught in certain circumstances carrying burglar's tools, not only will they be introduced into evidence against you, but the fact you have them will be a criminal violation in and of itself. The way the law deals with all kinds of ambiguities like this is to look at intent: If I carry a screwdriver to repair a broken door on my own house, it's not a burglar's tool. If I carry it to break the lock on my neighbor's house, it is. Determining intent is up to a jury (or judge or judge's panel, depending on the legal system and the defendent's choices). It's outside the realm of mathematics, proof in the mathematical sense, or much other than human judgement. If an expert witness testifies something is an encryption algorithm, and the jury believes him more than the defense's expert witness who testifies it's a digital controller for a secret ice cream maker ... that's what it is. If the jury further believes that encryption algorithm was used in the furtherance of a crime ... the defendent is in trouble. -- Jerry - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Papers about Algorithm hiding ?
On Thursday 26 May 2005 22:51, Hadmut Danisch wrote: Hi, you most probably have heard about the court case where the presence of encryption software on a computer was viewed as evidence of criminal intent. http://www.lawlibrary.state.mn.us/archive/ctappub/0505/opa040381-0503.htm http://news.com.com/Minnesota+court+takes+dim+view+of+encryption/2100-1030_ 3-5718978.html Plenty of research has been done about information hiding. But this special court case requires algorithm hiding as a kind of response. Do you know where to look for papers about this subject? What about designing an algorithm good for encryption which someone can not prove to be an encryption algorithm? I don't agree with your conclusion that hiding algorithms is a requirement. I think there is a much better direction: spread more algorithms. If everyone is using crypto then how can that be relevant to the case? I would suggest that the best way to overcome this flawed view of cryptography by the judges is to have the operating systems install with GPG installed by default. Some of the better ones already install SSH by default. (In fact the thrust of the argument was flawed as the user's PC almost certainly had a browser with SSL installed. As HTTPS can be used to access webmail privately and as we have seen this was an El Qaeda means of secret communication, the presence of one more crypto tool as relevent is a stretch.) iang -- Advances in Financial Cryptography: https://www.financialcryptography.com/mt/archives/000458.html - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
