4 ms·
Nice! From PDF: Message 1 4d c9 68 ff 0e e3 5c 20 95 72 d4 77 7b 72 15 87 d3 6f a7 b2 1b dc 56 b7 4a 3d c0 78 3e 7b 95 18
by dchest 15y ago
Nice! From PDF:
Message 1
4d c9 68 ff 0e e3 5c 20 95 72 d4 77 7b 72 15 87
d3 6f a7 b2 1b dc 56 b7 4a 3d c0 78 3e 7b 95 18
af bf a2[00]a8 28 4b f3 6e 8e 4b 55 b3 5f 42 75
93 d8 49 67 6d a0 d1[55]5d 83 60 fb 5f 07 fe a2
Message 2
4d c9 68 ff 0e e3 5c 20 95 72 d4 77 7b 72 15 87
d3 6f a7 b2 1b dc 56 b7 4a 3d c0 78 3e 7b 95 18
af bf a2[02]a8 28 4b f3 6e 8e 4b 55 b3 5f 42 75
93 d8 49 67 6d a0 d1[d5]5d 83 60 fb 5f 07 fe a2
Common MD5 hash
008ee33a9d58b51cfeb425b0959121c9
- 0x0 15y agoWow, so only two bits flipped? That's pretty bad even if you're using md5 just as a simple checksum protection against transmission errors.
- rphlx 15y agoNot really. This collision required specific intent, and a great deal of compute power, to find. md5 is still adequate for accidental/random error detection because the universe doesn't (usually) spend many hundreds of hours on hundreds of GPUs to try to corrupt your data without you noticing :)
- snewman 15y agoThough sometimes it can seem that way. :)
- 0x0 15y agoFair point. I just kind of assumed that any collision would require quite a lot of flipped bits, because usually just one flipped bit is enough to cause an "avalanche" of changes in the hash sum. Would it be possible to find a collision where only one bit is flipped in the input?
- deleted 15y ago[deleted]
- tankenmate 15y agoIf you are trying to protect against transmission errors then md5 is a poor choice; it is expensive, it gives no guarantees as to how accurate it is, and has no ability to correct errors. If you want to protect against transmission errors, and possibly correct them, use CRCs; apart from the fact that they provide all three of the above, that's what they were designed for.
- tptacek 15y agoVery well optimized CRC is significantly faster than MD5, but note that MD5 is very fast. MD5 is also a poorer choice for UUID-type applications than the SHA-2 functions, which offer more flexibility in output size at not much cost in performance.