Birthday attack

9. Birthday attack

Birthday attacks are made against hash algorithms that are utilized to confirm the integrity of a message, software, or digital signature. A message prepared by a hash work delivers a message digest (MD) of fixed length, independent of the length of the info message; this MD interestingly portrays the message.

The birthday attack refers to the likelihood of discovering two arbitrary messages that produce a similar MD when handled by a hash function. In the event that an attacker calculates similar MD for his message as the client has, he can securely supplant the client's message with his, and the collector can not distinguish the substitution regardless of whether he looks at MDs..