Score:2

I understand the authentication procedure, but are replay attacks possible in these scenarios?

md flag

Would a replay attack be possible in any of these scenarios? My understanding is that in only images 3 & 4 it is possible.

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fgrieu avatar
ng flag
I guess $\mathsf{N_X}$ is a nonce. That $\mathsf{E(K_{AB},…)}$ means _symmetric encryption_ with a secret key assumed known by A and B only. That $\mathsf{E(PU_A,N_A])}$ means _asymmetric encryption_ of $\mathsf{N_A}$ with a public key which matching private key is assumed known by A only. That lack of opening $\mathsf[$ is poetic license. That $\mathsf{E(PR_B,…)}$ means _signature_ with a private key known by B only, even though signature is not encryption.
timberus avatar
md flag
Yes, that is how I understood the terms as well. I'm just a little confused on whether I am right in understanding which sequences are victim to a replay
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