[Enigmail] How to use fingerprints?

[Derek VerLee]

Alexander Dahl wrote:
> Hi,
> 
>> Some of my mates have attached their fingerprint in the mail sinature.
>> How can I use it? As I've understood it, I can get he complete key with
>> it, but how?
> 
> Take the last 8 digits as a key ID and pull it from a keyserver. As you
> can see with the fingerprint in my signature below: take CC87 10D0 and
> write it as 0xCC8710D0 when requesting from a keyserver. This doesn't
> apply to some old keys, but most should do well.
> 
> Greets
> Alex
> 

This might be a naive question, but isn't the point of fingerprint to 
provide a convenient way to verify you are seeing the correct key, when 
you are communicating over a channel where you have some other way of 
authenticating that person's identity, IE, on a phone where you can 
recognize their voice, or in person?  What additional information is 
given by the fingerprint at the end of the email?  If it is signed, we 
already know the key and we decide to trust it or not.  If it is not 
signed, all we know is that a person or persons A has sent and email, 
some person or persons B may have modified that email, before we see it, 
and it has a fingerprint which corresponds to some key pair, that we 
might decide to trust is controlled by person C, but in any case may or 
may not be the same as A or B.

_derek