MD5 Collision
Looks like the venerable MD5 cryptographic hash has developed a crack: A real MD5 collision. A team has published two different input streams which hash to the same MD5 value. Of course, because of the pigeonhole principle, everyone knew this had to happen. But no one had ever found a pair before.
Update (2024-03-22): Marc Stevens (via Hacker News):
Here is a 72-byte alphanum MD5 collision with 1-byte difference for fun[…] This is the first md5 collision with only printable ascii that I know of.
David Buchanan (via Hacker News):
The image in this tweet displays its own MD5 hash.
[…]
This was particularly tricky to make work because the image data in a PNG needs to have a valid adler32 checksum, and a valid crc32 checksum.
