The secret handshake protocol of Balfanz et al. relies on a Bilinear Diffie-Hellman assumption (in ROM) on certain elliptic curves. We show how to build secret handshake protocols secure under more standard cryptographic assumption of Computational Diffie Hellman(CDH), using a novel tool of CA-oblivious public key encryption, which is an encryption scheme s.t. neither the public key nor the ciphertext reveal any information about the Certification Authority (CA) which certified the public key. We construct such CA-oblivious encryption, and hence a handshake scheme, based on CDH (in ROM). The new scheme takes 3 communication rounds like the scheme of Balfanz et al., but it is about twice cheaper computationally, and it relies on a weaker computational assumption.
Category / Keywords: cryptographic protocols / identification protocols, privacy, public-key cryptography Publication Info: to be published in Asiacrypt 2004, preliminary one-page announcement in PODC 2004 Date: received 2 Jun 2004, last revised 1 Sep 2004 Contact author: stasio at ics uci edu Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation Version: 20040901:194142 (All versions of this report) Short URL: ia.cr/2004/133