2

I have read that a symmetric key cannot guarantee non-repudiation, but in Mark Stamp's book "Information Security: Principles and practice", he gives this strong mutual authentication protocol:

this link

This protocol uses symmetric key, so my question is: This protocol can guarantee non-repudiation although it uses a symmetric key?

while reading the chapter it wasn't completely clear about this.

Thank you in advance for all your answers.

Improve this question

1 Answer 1

Reset to default
1

I think this depends on whether the sender and receiver can both be fully trusted not to reveal or misuse the key.

A secret known by more than one entity is less of a secret.

So to have a guarantee, you would need to fully trust both ends. Which kind of undermines the concept of non-repudiation rather.

I believe that ISO 13888-2 provides some workarounds for the idea of non-repudiation for symmetric key systems, I think it requires trusted 3rd parties to be involved though.

So I think that you can see that non-repudiation is generally rather more robust when using asymmetric keys.

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .