Uniqueness of Rev. Hex Id.s

[Gregory Szorc]

On 1/25/2014 8:40 AM, Pietro Moras wrote:
> Summarizing info so far received on the subject:
> 
> --"Secure Hash Algorithm"/SHA-1/, 40 hex digits, all used internally,
> first 12 in display.
> 
> --Odds of collision for the 12 digits are one in 16 million, relatively
> harmless (i.e.: easy to recover).
> 
> Anything to add? Remarks? Thanks!

It might be worth adding that it's effectively the same mechanism as
Git. Content being hashed isn't exactly the same, which is why the
SHA-1's are different. But the principles are very similar.