Public key fingerprint vs Digital Signature

Question

How do the Public key fingerprint and Digital Signature differs ? Or both are same ? if they are different, what is the application of public key fingerprint ?

Thanks

Answer 1

a public key fingerprint is a short sequence of bytes used to authenticate or look up a longer public key. Fingerprints are created by applying a cryptographic hash function to a public key. Since fingerprints are shorter than the keys they refer to, they can be used to simplify certain key management tasks

A digital signature is a mathematical scheme for demonstrating the authenticity of a digital message or document. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, and that it was not altered in transit. Digital signatures are commonly used for software distribution, financial transactions, and in other cases where it is important to detect forgery or tampering

A public key fingerprint is a short version of a public key which is used to authenticate a longer public key, if they do not match that means that the longer public key has been tampered with. So basically a digital signature is something that is signed by a user which only that user can sign so you can be sure that it is coming from that user.

So a public key fingerprint is used by a client and the digital signature is used by the server

Answer 2

The fingerprint is the hash of a key. A digital signature is tied to some message, and is typically a one-way encrypted hash of the message.

The two serve different purposes: You can put the public key fingerprint on your card or, if you recognize the other person on the phone, use it to verify you got the right public key(s). It doesn't say anything by itself. The digital signature, on the other hand, says that the message was signed with that key over there, and you don't need any other channel for verification of that fact.