Enhacement proposal: fingerprint

[mpancorbo]

A small fingerprint can be shown on screen after pw entry. It should depend on all parameters: special chars yes/no, length of digested pw, etc.

I propose something like sha512(orig pw | digested pw in ascii form) and take the lowest bits encoded, for example, as base32 (see Crockford's alfabet as reference). 6 characters (= 30 bits) may be a good compromise among collision resistance and quick visibilty (for example, when checking it in a list).

This can be a safe method to quick check if the pw was correctly typed. The user may maintain a list with all sites/services where he/she applies passera with each fingerprint besides each entry.