Revisiting Full-PRF-Secure PMAC and Using It for Beyond-Birthday Authenticated Encryption

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• 关键词：Symmetric cryptography ; Message authentication codes ; Authenticated encryption ; Provable security
• 刊名：Lecture Notes in Computer Science
• 出版年：2017
• 出版时间：2017
• 年：2017
• 卷：10159
• 期：1
• 页码：258-274
• 丛书名：Topics in Cryptology ?CT-RSA 2017
• ISBN：978-3-319-52153-4
• 卷排序：10159

文摘

This paper proposes an authenticated encryption scheme, called SIVx, that preserves BBB security also in the case of unlimited nonce reuses. For this purpose, we propose a single-key BBB-secure message authentication code with 2n-bit outputs, called PMAC2x, based on a tweakable block cipher. PMAC2x is motivated by PMAC_TBC1k by Naito; we revisit its security proof and point out an invalid assumption. As a remedy, we provide an alternative proof for our construction, and derive a corrected bound for PMAC_TBC1k.