Fast hash function with collision possibility near SHA-1

Question

I\'m using SHA-1 to detect duplicates in a program handling files. It is not required to be cryptographic strong and may be reversible. I found this list of fast hash functions

Answer 1

It kind of depends on how many hashes you are going to compute over in an iteration. Eg, 64bit hash reaches a collision probability of 1 in 1000000 with 6 million hashes computed.

Refer to : Hash collision probabilities