MD5 Collision Demo Collisions in the MD5 cryptographic hash function It is now well-known that the crytographic hash function MD5 has been broken. In March 2005, Xiaoyun Wang and Hongbo Yu of Shandong University in China published an article in which they describe an algorithm that can find two different sequences of 128 bytes with the same MD5 hash. One famous such pair is the following: d131dd..