谁可以告诉我md5加密原理

2004年，已经被山东大学的王小云教授破解了。

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以下是她在国际密码学会上发表的破解原理论文。

Collisions for Hash Functions

Collisions for Hash Functions

MD4, MD5, HAVAL-128 and RIPEMD

Xiaoyun Wang1, Dengguo Feng2, Xuejia Lai3, Hongbo Yu1

The School of Mathematics and System Science, Shandong University, Jinan250100, China1

Institute of Software, Chinese Academy of Sciences, Beijing100080, China2

Dept. of Computer Science and Engineering, Shanghai Jiaotong University, Shanghai, China3

xywang@sdu.edu.cn1

revised on August 17, 2004

1 Collisions for MD5

MD5 is the hash function designed by Ron Rivest [9] as a strengthened version of MD4 [8]. In 1993 Bert den

Boer and Antoon Bosselaers [1] found pseudo-collision for MD5 which is made of the same message with two

different sets of initial value. H. Dobbertin[3] found a free-start collision which consists of two different 512-bit

messages with a chosen initial value 0 V I .

ED BA x C B F x C B AC x A V I 763 4 0 D , 97 62 5 0 , 341042 3 0x B , 2375 12 0 : 0 0 0 0 0

Our attack can find many real collisions which are composed of two 1024-bit messages with the original

initial value 0 IV of MD5:

10325476 0 , 98 0 , 89 0 67452301 0 : 0 0 0 0 0 x D badcfe x C xefcdab ,B x A IV

) 0 , 2 ,..., 2 ,..., 2 , 0 , 0 , 0 , 0 ( , 31 15 31

1 1 C C M M

) 0 , 2 ,..., 2 ,..., 2 , 0 , 0 , 0 , 0 ( , 31 15 31

2 2 C C N N i i

(non-zeros at position 4,11 and 14)

such that

) , ( 5 ) , ( 5 i i N M MD N M MD .

On IBM P690, it takes about one hour to find such M and M , after that, it takes only 15 seconds to 5

minutes to find i N and i N , so that ) , ( i N M and ) , ( i N M will produce the same hash same value. Moreover,

our attack works for any given initial value.

The following are two pairs of 1024-bit messages producing collisions, the two examples have the same 1-st

half 512 bits.

M

2dd31d1 c4eee6c5 69a3d69 5cf9af98 87b5ca2f ab7e4612 3e580440 897ffbb8

634ad55 2b3f409 8388e483 5a417125 e8255108 9fc9cdf7 f2bd1dd9 5b3c3780

X1

N1

d11d0b96 9c7b41dc f497d8e4 d555655a c79a7335 cfdebf0 66f12930 8fb109d1

797f2775 eb5cd530 baade822 5c15cc79 ddcb74ed 6dd3c55f d80a9bb1 e3a7cc35

M0

2dd31d1 c4eee6c5 69a3d69 5cf9af98 7b5ca2f ab7e4612 3e580440 897ffbb8

634ad55 2b3f409 8388e483 5a41f125 e8255108 9fc9cdf7 72bd1dd9 5b3c3780

X1

N1

d11d0b96 9c7b41dc f497d8e4 d555655a 479a7335 cfdebf0 66f12930 8fb109d1

797f2775 eb5cd530 baade822 5c154c79 ddcb74ed 6dd3c55f 580a9bb1 e3a7cc35

H 9603161f f41fc7ef 9f65ffbc a30f9dbf

M

2dd31d1 c4eee6c5 69a3d69 5cf9af98 87b5ca2f ab7e4612 3e580440 897ffbb8

634ad55 2b3f409 8388e483 5a417125 e8255108 9fc9cdf7 f2bd1dd9 5b3c3780

X2

N2

313e82d8 5b8f3456 d4ac6dae c619c936 b4e253dd fd03da87 6633902 a0cd48d2

42339fe9 e87e570f 70b654ce 1e0da880 bc2198c6 9383a8b6 2b65f996 702af76f

M0

2dd31d1 c4eee6c5 69a3d69 5cf9af98 7b5ca2f ab7e4612 3e580440 897ffbb8

634ad55 2b3f409 8388e483 5a41f125 e8255108 9fc9cdf7 72bd1dd9 5b3c3780

313e82d8 5b8f3456 d4ac6dae c619c936 34e253dd fd03da87 6633902 a0cd48d2

42339fe9 e87e570f 70b654ce 1e0d2880 bc2198c6 9383a8b6 ab65f996 702af76f

H 8d5e7019 6324c015 715d6b58 61804e08

Table 1 Two pairs of collisions for MD5

2 Collisions for HAVAL-128

HAVAL is proposed in [10]. HAVAL is a hashing algorithm that can compress messages of any length in 3,4

or 5 passes and produce a fingerprint of length 128, 160, 192 or 224 bits.

Attack on a reduced version for HAVAL was given by P. R. Kasselman and W T Penzhorn [7], which

consists of last rounds for HAVAL-128. We break the full HAVAL-128 with only about the 26 HAVAL

computations. Here we give two examples of collisions of HAVAL-128, where

) 0 ,..., 0 , 2 ,.... 2 , 0 , 0 , 0 , 2 ( , 8 12 1 i i i C C M M

with non-zeros at position 0,11,18, and 31 ,... 2 , 1 , 0 i , such that ) ( ) ( M HAVAL M HAVAL .

M1

6377448b d9e59f18 f2aa3cbb d6cb92ba ee544a44 879fa576 1ca34633 76ca5d4f

a67a8a42 8d3adc8b b6e3d814 5630998d 86ea5dcd a739ae7b 54fd8e32 acbb2b36

38183c9a b67a9289 c47299b2 27039ee5 dd555e14 839018d8 aabbd9c9 d78fc632

fff4b3a7 40000096 7f466aac fffffbc0 5f4016d2 5f4016d0 12e2b0 f4307f87

M1

6377488b d9e59f18 f2aa3cbb d6cb92ba ee544a44 879fa576 1ca34633 76ca5d4f

a67a8a42 8d3adc8b b6e3d814 d630998d 86ea5dcd a739ae7b 54fd8e32 acbb2b36

38183c9a b67a9289 c47299ba 27039ee5 dd555e14 839018d8 aabbd9c9 d78fc632

fff4b3a7 40000096 7f466aac fffffbc0 5f4016d2 5f4016d0 12e2b0 f4307f87

H 95b5621c ca62817a a48dacd8 6d2b54bf

M2

6377448b d9e59f18 f2aa3cbb d6cb92ba ee544a44 879fa576 1ca34633 76ca5d4f

a67a8a42 8d3adc8b b6e3d814 5630998d 86ea5dcd a739ae7b 54fd8e32 acbb2b36

38183c9a b67a9289 c47299b2 27039ee5 dd555e14 839018d8 aabbd9c9 d78fc632

fff4b3a7 40000096 7f466aac fffffbc0 5f4016d2 5f4016d0 12e2b0 f5b16963

6377488b d9e59f18 f2aa3cbb d6cb92ba ee544a44 879fa576 1ca34633 76ca5d4f

a67a8a42 8d3adc8b b6e3d814 d630998d 86ea5dcd a739ae7b 54fd8e32 acbb2b36

38183c9a b67a9289 c47299ba 27039ee5 dd555e14 839018d8 aabbd9c9 d78fc632

fff4b3a7 40000096 7f466aac fffffbc0 5f4016d2 5f4016d0 12e2b0 f5b16963

H b0e99492 d64eb647 5149ef30 4293733c

Table 2 Two pairs of collision, where i=11 and these two examples differ only at the last word

3 Collisions for MD4

MD4 is designed by R. L. Rivest[8] . Attack of H. Dobbertin in Eurocrypto'96[2] can find collision with

probability 1/222. Our attack can find collision with hand calculation, such that

) 0 , 0 , 0 , 2 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 2 2 , 2 , 0 ( , 16 31 28 31 C C M M

and ) ( 4 ) ( 4 M MD M MD .

M1

4d7a9c83 56cb927a b9d5a578 57a7a5ee de748a3c dcc366b3 b683a020 3b2a5d9f

c69d71b3 f9e99198 d79f805e a63bb2e8 45dd8e31 97e31fe5 2794bf08 b9e8c3e9

M1

4d7a9c83 d6cb927a 29d5a578 57a7a5ee de748a3c dcc366b3 b683a020 3b2a5d9f

c69d71b3 f9e99198 d79f805e a63bb2e8 45dc8e31 97e31fe5 2794bf08 b9e8c3e9

H 5f5c1a0d 71b36046 1b5435da 9b0d807a

M2

4d7a9c83 56cb927a b9d5a578 57a7a5ee de748a3c dcc366b3 b683a020 3b2a5d9f

c69d71b3 f9e99198 d79f805e a63bb2e8 45dd8e31 97e31fe5 f713c240 a7b8cf69

4d7a9c83 d6cb927a 29d5a578 57a7a5ee de748a3c dcc366b3 b683a020 3b2a5d9f

c69d71b3 f9e99198 d79f805e a63bb2e8 45dc8e31 97e31fe5 f713c240 a7b8cf69

H e0f76122 c429c56c ebb5e256 b809793

Table 3 Two pairs of collisions for MD4

4 Collisions for RIPEMD

RIPEMD was developed for the RIPE project (RACE Integrrity Primitives Evalustion, 1988-1992). In

1995, H. Dobbertin proved that the reduced version RIPEMD with two rounds is not collision-free[4]. We show

that the full RIPEMD also isnOt collision-free. The following are two pairs of collisions for RIPEMD:

) 2 , 0 , 0 , 0 , 0 , 2 2 , 0 , 0 , 0 , 0 , 0 , 0 , 2 , 0 , 0 , 0 ( , 31 31 18 20 ' C C M M i i

M1

579faf8e 9ecf579 574a6aba 78413511 a2b410a4 ad2f6c9f b56202c 4d757911

bdeaae7 78bc91f2 47bc6d7d 9abdd1b1 a45d2015 817104ff 264758a8 61064ea5

M1

579faf8e 9ecf579 574a6aba 78513511 a2b410a4 ad2f6c9f b56202c 4d757911

bdeaae7 78bc91f2 c7c06d7d 9abdd1b1 a45d2015 817104ff 264758a8 e1064ea5

H 1fab152 1654a31b 7a33776a 9e968ba7

M2

579faf8e 9ecf579 574a6aba 78413511 a2b410a4 ad2f6c9f b56202c 4d757911

bdeaae7 78bc91f2 47bc6d7d 9abdd1b1 a45d2015 a0a504ff b18d58a8 e70c66b6

579faf8e 9ecf579 574a6aba 78513511 a2b410a4 ad2f6c9f b56202c 4d757911

bdeaae7 78bc91f2 c7c06d7d 9abdd1b1 a45d2015 a0a504ff b18d58a8 670c66b6

H 1f2c159f 569b31a6 dfcaa51a 25665d24

Table 4 The collisions for RIPEMD

5 Remark

Besides the above hash functions we break, there are some other hash functions not having ideal security. For

example, collision of SHA-0 [6] can be found with about 240 computations of SHA-0 algorithms, and a collision

for HAVAL-160 can be found with probability 1/232.

Note that the messages and all other values in this paper are composed of 32-bit words, in each 32-bit word

the most left byte is the most significant byte.

1 B. den Boer, Antoon Bosselaers, Collisions for the Compression Function of MD5, Eurocrypto,93.

2 H. Dobbertin, Cryptanalysis of MD4, Fast Software Encryption, LNCS 1039, D. , Springer-Verlag, 1996.

3 H. Dobbertin, Cryptanalysis of MD5 compress, presented at the rump session of EurocrZpt'96.

4 Hans Dobbertin, RIPEMD with Two-round Compress Function is Not Collision-Free, J. Cryptology 10(1),

1997.

5 H. Dobbertin, A. Bosselaers, B. Preneel, "RIPMEMD-160: A Strengthened Version of RIPMMD," Fast

Software EncrZption, LNCS 1039, D.Gollmann, Ed., Springer-Verlag, 1996, pp. 71-82.

6 FIPS 180-1, Secure hash standard, NIST, US Department of Commerce, Washington D. C., April 1995.

7 P. R. Kasselman, W T Penzhorn , Cryptananlysis od reduced version of HAVAL, Vol. 36, No. 1, Electronic

Letters, 2000.

8 R. L. Rivest, The MD4 Message Digest Algorithm, Request for Comments (RFC)1320, Internet Activities

Board, Internet Privacy Task Force, April 1992.

9 R. L Rivest, The MD5 Message Digest Algorithm, Request for Comments (RFC)1321, Internet Activities

Board, Internet PrivacZ Task Force, April 1992.3RIPEMD-1281

10 Y. Zheng, J. Pieprzyk, J. Seberry, HAVAL--A One-way Hashing Algorithm with Variable Length of Output,

Auscrypto'92.

我想学习编程，但是不知道该怎么开始。

我建议最好是从基础入手，而不是一开始就进行可视化编程。虽然如今国内绝大多数pc都是使用的windows，但是毕竟这知识这个世界的冰山一角。扎实的基础自然会更有用处。编程其实重要的是程序思维，然后是算法和数据结构。这些都是超出语言的，就是说不管是学c学java学delphi还是别的什么，这一部分都是一致的。因此培养这部分的知识可以说是一本万利的事情。初学肯定是通过语言熟悉思想熟悉算法和数据结构，到一定的时候就是纯粹的思想和算法数据结构的学习，便已经脱离程序语言了。经历过这些阶段，换一种语言不过是重新了解一下描述的方式，就像你了解了中文思维，山东话和四川话的差别就不会太大；了解了拉丁语的思维，整个语系的语言都不过是简简单单的记忆工作，应用就好。入门的语言，理论上是怎么方便学哪个，看那个顺眼学哪个。当然这里面还是有不同的推荐的。一般来说我比较推荐pascal、c/c++、java。并不是因为这三个东西很通用很有前途，而是它们实在是严整而有规则（c/c++还显得稍微的宽松了一点），而严谨的语法要求和明确的概念区分是有利于编程思维的形成和算法数据结构的学习的。同样的因为这个理由我不推荐vb，而并不是因为它功能不强大（事实上vb在windows环境中是相当牛的语言）另外一个建议是，如果学c，不要一开始就用vc。ms提供的很多东西很方便，有很多很简单的实现方法，但是它们不标准。vc与ansi

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ansi

c标准，无论它的c还是c++编译器都很严整，功能上一点也不缺乏（有人说gcc不能做图形界面的程序，这一点完全错误，到处都有的qt库和gtk库都能做出很好的界面），另外一个理由便是它免费，毕竟稍微大一点的软件企业就不会屈从与微软的编译器和平台，而一个免费的c编译器无疑可以创造更多的利益；就算要转vc，标准的c程序也是几乎不要作任何改动的。当然，这一切的前提是，你真的很想很好的学编程，做一个这方面的精英。如果只不过是兴趣，或者只是想拿一个ms的工程师认证然后在国内企业找份诸如设计vf、vb程序之类的工作，那完全可以忽略我上面的话，去找个认证培训班，认认真真听听课，好好完成练习，从vb或者vc入手，考好认证是很不会太难的。毕竟现在很多很好的大学里都从来不缺乏计算机的课程，不会缺少算法或者编译原理的课程，不会没有计算机科学的研究院，而那里面出来的人一般都具备了很好的基础知识，会更加容易成为前面所说的精英。

济南大学的SQA项目整体怎么样？

济南大学的SQL项目现在已经做得非常好了整体项目已经达到了一定的标准，所以现在可以这边看一看考察一下。

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