A Study on Efficient Identification Schemes Secure against Concurrent Man-in-the-Middle Attacks
Hiroaki Anada · 2012
We tackle the problem of constructing public key-based identification schemes (ID schemes) that are secure against concurrent man-in-the-middle attacks (cMiM at-tacks). Here, a concurrent man-in-the-middle attack means an active attack in which an adversary interacts with a victim verifier trying to impersonate a prover, while the adversary collects information of the secret key interacting concurrently with provers that have the same secret key. Our approach is not based on the Σ-protocols but on key encapsulation mecha-nisms (KEMs). First, we propose a generic conversion from a KEM to an ID scheme. Although this is a straightforward conversion, there exists a possibility of realizing efficient cMiM secure ID schemes because a KEM only has to be secure against adaptive chosen ciphertext attacks on one-wayness (one-way-CCA2 secure) for the derived ID scheme to be cMiM secure. Next, looking at the generic conversion as a design principle, we develop a series of concrete KEMs to get ID schemes. We start with El Gamal KEM and prove it to