Modeling Noise-Accepting Key Exchange.

In this paper we use code-based public key encryption schemes to construct key exchange protocols that are suitable for use in the presence of transmission bit-errors, such as in mobile ad hoc networks. Building upon the security model by Bellare and Rogaway [ 2 ], we let instances that have matching conversations up to a certain error bound generate the same session key. In order to prevent an adversary from trivially attacking the schemes, a relaxed version of matching conversation is introduced and shown to be well-defined. To give validity to our model we show that the introduced security model can be reduced to the original Bellare and Rogaway-security model. Additionally, we prove the naive and obvious solution of adding error correction to a key exchange protocol will not affect the security of the protocol. Finally, we introduce the concept of error-resistant asymmetric schemes and key encapsulations. Then through a modified Fujisaki-Okamoto-transform we show that a probabilistic error-resistant asymmetric scheme can be transformed into an error-resistant key encapsulation mechanism (KEM). A key exchange protocol construction based on the transformed KEM’s is then presented and proven secure.