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Freestart collision for 76-steps SHA-1

Pierre Karpman (NTU,Inria), Thomas Peyrin (NTU), Marc Stevens (CWI)

Details

Our rump session presentation can be found here.

We have found an example colliding message pair (do your own verification using this software):

Unrolled Internal State Words Q-4,...,Q76:
-4 11110001010000100001111000100011
-3 11101001010000001010001101010110
-2 000011111010011010011110001111+0
-1 0100000110111000001110110101110+
 0 10000001101111110010001100000110

 1 100100011001100111100000000+0110
 2 00111-1101101101111100+110111-11
 3 10000-01011110010+000011-1001-00
 4 0-0100111001+101100-1111-10010+1
 5 1+001010001110-0101-000111+0+110
 6 000-1-1-1--++++001+0-1--1110100-
 7 1+0-1+-0-+10+-00++-+11100+010111
 8 +-1100+-------------1-++110-11+0
 9 --+001101011000010+-001100-11101
10 -1001011100011101100100111011001
11 111-1111100111001001101000011100
12 +0+10101011101101100111101011011
13 01+01011111111010001011000-10000
14 00+00001101101110001101001000101
15 1-110100100001101111110111011011
16 +0010001010001100111101000011110
17 +1-11001101101100001000010111100
18 +0001011010100101001111010000100
19 1-011001100001101010111101000001
20 -0010001100110011000110111011110
21 -1-10010100100001000000011101110
22 -1000001101101000111110101011101
23 -0+10101011010110111000111101010
24 00111101110100010111001101111101
25 11-00111011000110011001100000011
26 -0000100110110110101010100101001
27 0--10011111000100100010101011001
28 11011110100011000011001011100001
29 00010001011001010111011110111010
30 -0010000010001110100000000111000
31 -0011001111000101110101110011101
32 01010000010001111100100011000100
33 11111011101100101110011101100000
34 01010110110001101001100011001101
35 10101000100100010011010010110011
36 00000001100001110010100111111111
37 -0000111011010010010110111000011
38 01101100101010001001000111110100
39 +0110110010010000101101000000111
40 11101011011111010111111100101001
41 -1000111100011110100000101001010
42 00000110000100100010000111011011
43 1+100100000010110000110101110100
44 10011010110000111011001111111101
45 10010100001011110100100001111110
46 +1011111110011011000111001011010
47 01010011101111011100010111101101
48 00111101011100001010111101010111
49 10101111110000001100100011101010
50 00101010111111010010111110001101
51 +1010000001010000101111000000100
52 01111100100001110000101100011010
53 11101010100110111011010111101110
54 00011101001010111100101101110101
55 00001110000000101010000111110101
56 01111100110101111010001111001110
57 -1000000110100011011110011100011
58 00111000101000101001011111011010
59 -0010110110101001001001111011101
60 01110110001111110000100100010010
61 10101100011111010000001101100010
62 11001111110101111110110100110000
63 10001001111101110110000011100110
64 10110101110101101011110001101111
65 00111011101100110101110011101011
66 11010011001111101001011111110111
67 10110011010001000001100111001000
68 01001010111111110010110100001010
69 11000010111001011010111100101011
70 01110111111011010101000100001011
71 0011100100111110110101000110101+

72 01101010001010000110111001110011
73 10001010010111110010101101111000
74 100000101101001001111011101001-1
75 0001000011001001111110011010011-
76 00101101100010100011101000001010

Output Chaining Value:
 0 10101111010010010101110100010000
 1 01010010100000100011010100000011
 2 11100100100111100100011001111000
 3 11011100111001111111001110110011
 4 11010110110110101010001100100100

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