Cryptography-Digest Digest #388
Cryptography-Digest Digest #388, Volume #14 Fri, 18 May 01 22:13:01 EDT
Contents:
Re: TC15a x86 FYI (Tom St Denis)
Re: Apology to Cloakware (open letter) (Paul Pires)
Re: OT lethal force; was: ON-topic - UK crime statistics (was Re: Best,Strongest
Algorithm) ([EMAIL PROTECTED])
Re: TC15a x86 FYI (bubba)
Re: Apology to Cloakware (open letter) (Darren New)
Re: TC15a x86 FYI (Tom St Denis)
Re: Apology to Cloakware (open letter) (Tom St Denis)
Re: Apology to Cloakware (open letter) (Just Looking)
Re: What about SDD? (Rob Warnock)
Re: Apology to Cloakware (open letter) (Tom St Denis)
Re: TC15a x86 FYI (Tom St Denis)
Re: truth+integrity=sore losers (Eric Lee Green)
From: Tom St Denis [EMAIL PROTECTED]
Subject: Re: TC15a x86 FYI
Date: Sat, 19 May 2001 00:18:43 GMT
bubba [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED]...
With my Pentium III and Windows 2000, I get 263
for the Intel code. Not bad for compiler code,
but after comparing the two, it seems like the
numbers should be a little closer. I get 200
from your executable, so my system must be running
like other Pentium IIIs. The 200 becomes 198 by
raising the priority.
I compiled the C code optimized for P4 only, and
the 263 went to 315 on the PentiumIII (I have no
Pentium4 here at home). Here is the Pentium4 code.
It will make you reread the Pentium4 optimization
rules before you believe what you see. Pentium 4
is especially slow on today's code.
I get about 250 cycles per block using GCC on my Athlon Tbird... Seems GCC
is a decent optimizing compiler :-)
By the way, for Microsoft Outlook express users,
I noticed that you can make it display plain text
in a fixed font, which it does not do by default.
The following is much easier to read with a fixed font.
Thanks for the info. It's neat to see the intel compiler output (I don't
have the intel compiler...)
27:
28: /* copy */
29: a = in[0];
0040101F 8B 2Emov ebp,dword ptr [esi]
30: b = in[1];
00401021 8B 4E 04 mov ecx,dword ptr [esi+4]
31: c = in[2];
00401024 8B 56 08 mov edx,dword ptr [esi+8]
32: d = in[3];
00401027 8B 46 0C mov eax,dword ptr [esi+0Ch]
33:
34: /* 8 rounds */
35: for (r = 0; r 8; r++) {
0040102A 33 FFxor edi,edi
0040102C 89 7C 24 04 mov dword ptr [esp+4],edi
36: /* mix in key words */
37: a ^= key[4*r+0];
00401030 8B 7B 08 mov edi,dword ptr [ebx+8]
00401033 8B 74 24 04 mov esi,dword ptr [esp+4]
00401037 33 2C 3E xor ebp,dword ptr [esi+edi]
41:
42: /* LT */
43: a = ROTL(a, 1);
0040103A D1 C5rol ebp,1
38: b ^= key[4*r+1];
0040103C 33 4C 3E 04 xor ecx,dword ptr [esi+edi+4]
39: c ^= key[4*r+2];
00401040 33 54 3E 08 xor edx,dword ptr [esi+edi+8]
44: b = ROTL(b, 9);
00401044 C1 C1 09 rol ecx,9
45: c = ROTL(c, 17);
00401047 C1 C2 11 rol edx,11h
40: d ^= key[4*r+3];
0040104A 33 44 3E 0C xor eax,dword ptr [esi+edi+0Ch]
46: temp = (c*3) + (d*9);
0040104E 8D 3C 12 lea edi,[edx+edx]
00401051 8D 34 00 lea esi,[eax+eax]
00401054 03 FAadd edi,edx
00401056 03 F6add esi,esi
00401058 03 F6add esi,esi
0040105A 03 F0add esi,eax
0040105C 03 FEadd edi,esi
47: a += temp;
0040105E 03 EFadd ebp,edi
48: b -= temp;
00401060 2B CFsub ecx,edi
49: temp = (a*3) + (b*9);
00401062 8D 7C 2D 00 lea edi,[ebp+ebp]
00401066 8D 34 09 lea esi,[ecx+ecx]
00401069 03 FDadd edi,ebp
0040106B 03 F6add esi,esi
0040106D 03 F6add esi,esi
0040106F 03 F1add esi,ecx
00401071 03 FEadd edi,esi
50: c += temp;
00401073 03 D7add edx,edi
51: d -= temp;
00401075 2B C7sub eax,edi
52:
53: /* bitslice 4x4 */
54: a ^= b^(cd);
00401077 8B F2mov esi,edx
00401079 23 F0and esi,eax
0040107B 33 F1xor esi,ecx
0040107D 33 EExor ebp,esi
55: b ^= c^(d|a);
0040107F 8B F0mov esi,eax
00401081 0B F5or esi,ebp
00401083 33 F2xor esi,edx
00401085 33 CExor
Cryptography-Digest Digest #388
Cryptography-Digest Digest #388, Volume #11 Wed, 22 Mar 00 11:13:01 EST
Contents:
Re: Concerning UK publishes "impossible" decryption law (Richard Herring)
Re: Concerning UK publishes "impossible" decryption law (Richard Herring)
Re: Non-doublespending offline digital money? (Tony L. Svanstrom)
Re: multiple encryption (Johnny Bravo)
Re: multiple encryption (Mark Wooding)
Re: new Echelon article (Richard Herring)
2nd CFV: sci.crypt.random-numbers (Dave Cornejo)
Re: Playfair cipher ([EMAIL PROTECTED])
Re: Factoring Large Numbers - I think I figured it out! (Bob Silverman)
Re: multiple encryption ([EMAIL PROTECTED])
Hashing Algorithms. (basic newbie question) ("@")
Re: Factoring Large Numbers - I think I figured it out! (Lincoln Yeoh)
Re: key distribution/management (Paul Koning)
Re: key distribution/management (Paul Koning)
Re: pgp key collision (Paul Koning)
From: [EMAIL PROTECTED] (Richard Herring)
Crossposted-To:
alt.security.pgp,comp.security.pgp.discuss,alt.security.scramdisk,alt.privacy
Subject: Re: Concerning UK publishes "impossible" decryption law
Date: 22 Mar 2000 13:08:10 GMT
Reply-To: [EMAIL PROTECTED]
In article 8b8rvq$eop$[EMAIL PROTECTED], Otto Sykora
([EMAIL PROTECTED]) wrote:
an electric magnet is not so hard to make or get hold of, its
harmless
unless power is given to it, and when powered, can be easily be strong
enough to destroy data an the disks.
I find that difficult to believe Can you provide figures to
justify your assertion?
why should it be difficult to destroy data on disk with a magnet?
***
Small example , this time with small permanent magnet:
in some trains in Germany, they have seats similar like in airplane,
the small table integrated in the seat in front of you is held in the
stoved position by two small permament magnets. When people used this
table as support for some types of laptop computer, their harddrivs
were sudenly partialy erased. Just because of the small magnet placed
abt half inch from the drive.
"Partially erased" is not the same thing as "destroyed".
The question here is, are you certain that this method will wipe
*all* your sensitive data, such that even a major government agency
equipped with x-rays, electron microscopes, SQUID magnetometers
(or whatever they actually use - I have no idea) cannot recover
any trace of it? Are you confident enough to stake your liberty
or life on it?
--
Richard Herring | [EMAIL PROTECTED]
--
From: [EMAIL PROTECTED] (Richard Herring)
Crossposted-To:
alt.security.pgp,comp.security.pgp.discuss,alt.security.scramdisk,alt.privacy
Subject: Re: Concerning UK publishes "impossible" decryption law
Date: 22 Mar 2000 13:16:54 GMT
Reply-To: [EMAIL PROTECTED]
Distribution:
In article [EMAIL PROTECTED], ÐRëÐÐ ([EMAIL PROTECTED]) wrote:
quantitive data, im afraid i am not very up on electronics as much as i
would like to be, of course your request works both ways, can you disprove
the posibilty of a magnetic feild powered by the pc to destroy/damage the
disk, switched on by a false login, powered through the paralel port?
Of course I can't disprove it. I understand how it would work, and
of course a large enough field will do some damage. The quantitative
question is, how large does the field have to be to destroy *all* your
data. Just damaging some of it is not sufficient.
But the request doesn't work both ways:
If I believe your method doesn't work when it does, I have overlooked
a cheap solution and may have to spend a little more time or money
finding a different method of destroying my sensitive data. Big deal.
But if you trust your method to work when it doesn't, you could find
yourself in jail, or worse, when They find the data you thought you
had destroyed.
im not
being a smart ass, and i might have shot my mouth off, but i am an idea's
man, and like to be proven conclusively wrong. not just flamed
No flame intended. But someone has to go from the ideas to the
implementation, and that means asking "engineering" questions like
how strong a magnet, and how reliable the outcome. I know enough
about the physics involved to have some doubt about its practicality.
--
Richard Herring | [EMAIL PROTECTED]
--
From: [EMAIL PROTECTED] (Tony L. Svanstrom)
Subject: Re: Non-doublespending offline digital money?
Date: Wed, 22 Mar 2000 14:30:44 +0100
matt [EMAIL PROTECTED] wrote:
Could anyone tell me if it is theoretically/physically possible to have a
digital cash system which is offline, and prevents double spending?
Just thinking about it, it seems impossible. But maybe someone knows some
really tricky maths etc...?
Well, if you can copy it then you
Cryptography-Digest Digest #388
Cryptography-Digest Digest #388, Volume #10 Mon, 11 Oct 99 06:13:02 EDT Contents: Cryptography FAQ (03/10: Basic Cryptology) ([EMAIL PROTECTED]) Cryptography FAQ (04/10: Mathematical Cryptology) ([EMAIL PROTECTED]) From: [EMAIL PROTECTED] Crossposted-To: talk.politics.crypto,sci.answers,news.answers,talk.answers Subject: Cryptography FAQ (03/10: Basic Cryptology) Date: 11 Oct 1999 09:45:14 GMT Reply-To: [EMAIL PROTECTED] Archive-name: cryptography-faq/part03 Last-modified: 93/10/10 This is the third of ten parts of the sci.crypt FAQ. The parts are mostly independent, but you should read the first part before the rest. We don't have the time to send out missing parts by mail, so don't ask. Notes such as ``[KAH67]'' refer to the reference list in the last part. The sections of this FAQ are available via anonymous FTP to rtfm.mit.edu as /pub/usenet/news.answers/cryptography-faq/part[xx]. The Cryptography FAQ is posted to the newsgroups sci.crypt, talk.politics.crypto, sci.answers, and news.answers every 21 days. Contents: 3.1. What is cryptology? Cryptography? Plaintext? Ciphertext? Encryption? Key? 3.2. What references can I start with to learn cryptology? 3.3. How does one go about cryptanalysis? 3.4. What is a brute-force search and what is its cryptographic relevance? 3.5. What are some properties satisfied by every strong cryptosystem? 3.6. If a cryptosystem is theoretically unbreakable, then is it guaranteed analysis-proof in practice? 3.7. Why are many people still using cryptosystems that are relatively easy to break? 3.8. What are the basic types of cryptanalytic `attacks'? 3.1. What is cryptology? Cryptography? Plaintext? Ciphertext? Encryption? Key? The story begins: When Julius Caesar sent messages to his trusted acquaintances, he didn't trust the messengers. So he replaced every A by a D, every B by a E, and so on through the alphabet. Only someone who knew the ``shift by 3'' rule could decipher his messages. A cryptosystem or cipher system is a method of disguising messages so that only certain people can see through the disguise. Cryptography is the art of creating and using cryptosystems. Cryptanalysis is the art of breaking cryptosystems---seeing through the disguise even when you're not supposed to be able to. Cryptology is the study of both cryptography and cryptanalysis. The original message is called a plaintext. The disguised message is called a ciphertext. Encryption means any procedure to convert plaintext into ciphertext. Decryption means any procedure to convert ciphertext into plaintext. A cryptosystem is usually a whole collection of algorithms. The algorithms are labelled; the labels are called keys. For instance, Caesar probably used ``shift by n'' encryption for several different values of n. It's natural to say that n is the key here. The people who are supposed to be able to see through the disguise are called recipients. Other people are enemies, opponents, interlopers, eavesdroppers, or third parties. 3.2. What references can I start with to learn cryptology? For an introduction to technical matter, the survey articles given in part 10 are the best place to begin as they are, in general, concise, authored by competent people, and well written. However, these articles are mostly concerned with cryptology as it has developed in the last 50 years or so, and are more abstract and mathematical than historical. The Codebreakers by Kahn [KAH67] is encyclopedic in its history and technical detail of cryptology up to the mid-60's. Introductory cryptanalysis can be learned from Gaines [GAI44] or Sinkov [SIN66]. This is recommended especially for people who want to devise their own encryption algorithms since it is a common mistake to try to make a system before knowing how to break one. The selection of an algorithm for the DES drew the attention of many public researchers to problems in cryptology. Consequently several textbooks and books to serve as texts have appeared. The book of Denning [DEN82] gives a good introduction to a broad range of security including encryption algorithms, database security, access control, and formal models of security. Similar comments apply to the books of Price Davies [PRI84] and Pfleeger [PFL89]. The books of Konheim [KON81] and Meyer Matyas [MEY82] are quite technical books. Both Konheim and Meyer were directly involved in the development of DES, and both books give a thorough analysis of DES. Konheim's book is quite mathematical, with detailed analyses of many classical cryptosystems. Meyer and Matyas concentrate on modern cryptographic methods, especially pertaining to key management and the integration of security facilities into computer systems and networks. For more recent documentation on related areas, try G. Simmons in [SIM91
