Efficient and Non-malleable Proofs of Plaintext Knowledge and Applications [chapter]

Jonathan Katz
2003 Lecture Notes in Computer Science  
We describe efficient protocols for non-malleable (interactive) proofs of plaintext knowledge for the RSA, Rabin, Paillier, and El Gamal encryption schemes. We also highlight some important applications of these protocols: -Chosen-ciphertext-secure, interactive encryption. In settings where both parties are on-line, an interactive encryption protocol may be used. We construct chosen-ciphertext-secure interactive encryption schemes based on any of the schemes above. In each case, the improved
more » ... eme requires only a small overhead beyond the original, semantically-secure scheme. -Password-based authenticated key exchange. We derive efficient protocols for password-based key exchange in the public-key model [28, 5] whose security may be based on any of the cryptosystems mentioned above. -Deniable authentication. Our techniques give the first efficient constructions of deniable authentication protocols based on, e.g., the RSA or computational Diffie-Hellman assumption. Of independent interest, we consider the concurrent composition of proofs of knowledge; this is essential to prove security of our protocols when run in an asynchronous, concurrent environment.
doi:10.1007/3-540-39200-9_13 fatcat:erwmazstcvcjjditr3ytdkvoim