Surprise! Another serious hole in Diebold voting machines...
...okay, not so much surprise. [...] Scientists said Diebold appeared to have opened the hole by making it as easy as possible to upgrade the software inside its machines. The result, said Iowa's Jones, is a violation of federal voting system rules. All of us who have heard the technical details of this are really shocked. It defies reason that anyone who works with security would tolerate this design, he said. [...] http://www.schneier.com/blog/archives/2006/05/ election_machin_1.html (http://tinyurl.com/rqw23) - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: Piercing network anonymity in real time
|The Locate appliance sits passively on the network and |analyzes packets in real time to garner ID info from sources |like Active Directory, IM and e-mail traffic, then associates |this data with network information. | | This is really nothing new -- I've been seeing systems like these, | though home brewed, in use for years. The availability of good tools as | a foundation (things like Snort, the layer7 iptables patch, and so on) | makes building decent layer 8 inference not far from trivial. Calling | this piercing network anonymity in real time is highly misleading; in | reality, it's more like making it bloody obvious that there's no such | thing as network anonymity. | | The best one can hope for today is a bit of anonymous browsing and IM | with Tor, and that only insofar as you can trust a system whose single | point of failure -- the directory service -- was, at least until | recently, Roger's personal machine sitting in an MIT dorm room. There's a difference between can be done by someone skilled and your IT can buy a box and have it running on your network this afternoon. The first basically means that most people, most of the time, effectively have anonymity because it isn't worth anyone's bother to figure out what they are up to. With the second, information about who you are, who you talk to, etc., etc., becomes a commodity - a very *cheap* commodity. Safety in numbers disappears. It's always been possible to go to town hall and look up public records like deeds - which often contain things like Social Security numbers, bank account numbers, etc. Skilled experts - PI's - have made use of this information for years. There's no difference, in principle, when that some information goes up on the web. But that's not how most people feel about it. -- Jerry - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: picking a hash function to be encrypted
* Travis H.: IIUC, protocol design _should_ be easy, you just perform some finite-state analysis and verify that, assuming your primitives are ideal, no protocol-level operations break it. Is this still true if you don't know your actual requirements? - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: the meaning of linearity, was Re: picking a hash function to be encrypted
| - Stream ciphers (additive) | | This reminds me, when people talk about linearity with regard to a | function, for example CRCs, exactly what sense of the word do they | mean? I can understand f(x) = ax + b being linear, but how exactly | does XOR get involved, and are there +-linear functions and xor-linear | functions? Are they disjoint? etc. XOR is the same as addition mod 2. The integers mod 2 form a field with XOR as the addition operation and integer multiplication (mod 2, though that has no effect in this case) as the multiplication. If you think of a stream of n bits as a member of the vector space of dimension n over the integers mod 2 treated as a field, then adding two of these - the fundamental linear operation - is XOR'ing them bit by bit. The thing I've always wondered about stream ciphers is why we only talk about linear ones. A stream cipher is fundamentally constructed of two things: A stream of bits (alleged to be unpredictable) as long as the plaintext; and a combining function that takes one plaintext bit and one stream bit and produces a ciphertext bit. The combining function has to conserve information. If you only combine single bits, there are only two possible functions: XOR and the complement of XOR. But consider RC4: It actually generates a byte at a time. We just choose to use that byte as a vector of 8 bits. For plaintexts that are multiples of 8 bits long - just about everything these days - there are many possible combining functions. Most aren't even close to linear. Other than post by a guy - Terry someone or another - on sci.crypt a number of years ago - I've never seen any work in this direction. Is there stuff I'm not aware of? -- Jerry - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: the meaning of linearity, was Re: picking a hash function to be encrypted
On 5/15/06, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: Other than post by a guy - Terry someone or another - on sci.crypt a number of years ago - I've never seen any work in this direction. Is there stuff I'm not aware of? That would probably be Terry Ritter, www.ciphersbyritter.com. He calls this function Dynamic Substitution: http://www.ciphersbyritter.com/#DynSubTech You could also probably use a Latin square: http://www.ciphersbyritter.com/#BBMTech -- Curiousity killed the cat, but for a while I was a suspect -- Steven Wright Security Guru for Hire http://www.lightconsulting.com/~travis/ -- GPG fingerprint: 9D3F 395A DAC5 5CCC 9066 151D 0A6B 4098 0C55 1484 - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Government using call records to go after reporter's sources.
One of ABC News' reporters says that he's been warned that call records, possibly even the ones that the major telecom companies are now routinely turning over to the NSA, are being used to track down the sources for reporters at several major news services. http://blogs.abcnews.com/theblotter/2006/05/federal_source_.html I realize many people might disagree with me, but from my point of view, the use of such heavy-handed counterintelligence tactics against the press is a substantial threat to freedom in this country. John Gilmore long ago warned us that once we'd built the total surveillance state, all that would be needed to build a new totalitarianism would be a change of attitude on the part of the governors. Well, we've built CALEA into everything, and we've built computerized systems for siphoning all call data in existence, and now we have an administration with, to say the least, a serious change in attitude about the law and morality. We have crossed a rubicon. It can be argued by some who do not agree with me that the reporters in question are somehow helping the terrorists by revealing things like the fact that the US Government has SigInt operations, but in fact anyone who isn't an idiot already knows we have SigInt operations. What the reporters have done -- heroically, I might add -- is reveal that the government has far exceeded the bounds of legality in performing such operations, even when legal methods existed to gain the same information. Some may call said reporters traitors, but it has become increasingly clear to me that the real traitors are those who do not respect the principles this country was founded on and who would sell our hard won freedom and mortgage the rule of law, not for security but for political gain. The surveillance against reporters is being used not to save lives but to save the administration political embarrassment, and there will be no end to the political uses of surveyance if it is not stopped now. I implore everyone who agrees with me not to be silent. If you do not call your representatives to complain about this, it will eventually be too late to complain. Tell them you want hearings with teeth, tell them that you want a special prosecutor, tell them that you do not want to see them rubber stamp universal surveillance with legal fig leaves, and that you will work to see someone else elected, no matter how much you like them otherwise, if they refuse to do anything about this issue. Tell your friends and family to make those calls as well. I do not know that screaming loudly about this will work, but I know what silence will bring. Perry - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: picking a hash function to be encrypted
Travis H. writes: Excellent point. When I wrote that I had strongly universal hashes in mind, like UMAC, where the hash is chosen from a family of functions based on some secret data shared by sender and recipient. I mistakenly conflated them with ordinary hashes (which they are, once you pick one). Thanks for catching that. A point of terminology, strong universal hash functions are different than what you are probably thinking of. UMAC is a MAC, not a SU hash function. It uses an almost-SU hash function in its construction, but that's different. Universal hashes and their variants (see http://www.cacr.math.uwaterloo.ca/~dstinson/universalhashingdefinitions.html for a bibliography) are actually *weaker* than conventional hashes. They can, in fact, be completely linear. While you are right that the hash is typically part of a parameterized family, once you pick one you do not get an ordinary hash. You are more likely to get an ordinary polynomial that will not serve at all well as a crypto hash. Hal Finney - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
Re: the meaning of linearity, was Re: picking a hash function to be encrypted
Travis H. wrote: - Stream ciphers (additive) This reminds me, when people talk about linearity with regard to a function, for example CRCs, exactly what sense of the word do they mean? I can understand f(x) = ax + b being linear, but how exactly does XOR get involved, and are there +-linear functions and xor-linear functions? Are they disjoint? etc. If you have a linear algebra book handy, look up linear transformation. Briefly, a function T from a vector space V to another vector space W (where V and W are defined over the same field) is called a linear transformation if it satisfies i) T(u +_V v) = T(u) +_W T(v) ii) T(c *_V u) = c *_V T(u) iii) T(0_V) = 0_W CRC is a linear transformation because CRC(u + v) = CRC(u)+CRC(v). -James - The Cryptography Mailing List Unsubscribe by sending unsubscribe cryptography to [EMAIL PROTECTED]
