# Verifying identity using a sha-1 hash

I was reading http://blog.zorinaq.com/?e=74 which is about a Windows kernel developer. The developer proves that he is an actual developer by posting the SHA1 hash of a particular revision of a file. The actual hash values have been redacted, but I would like to know how knowledge of the hash would prove this.

• I would disagree that it gives any credence whatsoever that he has access to the file. I say this because I have access to that file at that revision, and the SHA1 hash is actually fc4df56ce275e7981ee93a0c3138bfc68aa1d97a. – Stephen Touset Jan 19 '15 at 21:19