Abstract
Online ciphers encrypt an arbitrary number of plaintext blocks and output ciphertext blocks which only depend on the preceding plaintext blocks. All online ciphers proposed so far are essentially serial, which significantly limits their performance on parallel architectures such as modern general-purpose CPUs or dedicated hardware.We propose the first parallelizable online cipher, COPE. It performs two calls to the underlying block cipher per plaintext block and is fully parallelizable in both encryption and decryption. COPE is proven secure against chosenplaintext attacks assuming the underlying block cipher is a strong PRP. We then extend COPE to create COPA, the first parallelizable, online authenticated cipher with nonce-misuse resistance. COPA only requires two extra block cipher calls to provide integrity. The privacy and integrity of the scheme is proven secure assuming the underlying block cipher is a strong PRP. Our implementation with Intel AES-NI on a Sandy Bridge CPU architecture shows that both COPE and COPA are about 5 times faster than their closest competition: TC1, TC3, and McOE-G. This high factor of advantage emphasizes the paramount role of parallelizability on up-to-date computing platforms.
Original language | English |
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Title of host publication | Advances in Cryptology. 19th International Conference on the Theory and Application of Cryptology and Information Security |
Editors | Kazue Sako, Palash Sarkar |
Publisher | Springer |
Publication date | 2013 |
Pages | 424-443 |
ISBN (Print) | 978-3-642-42032-0 |
ISBN (Electronic) | 978-3-642-42033-7 |
DOIs | |
Publication status | Published - 2013 |
Event | 19th International Conference on the Theory and Application of Cryptology and Information Security: ASIACRYPT - Bengaluru, India Duration: 1 Dec 2013 → 5 Dec 2013 Conference number: 19 |
Conference
Conference | 19th International Conference on the Theory and Application of Cryptology and Information Security |
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Number | 19 |
Country/Territory | India |
City | Bengaluru |
Period | 01/12/2013 → 05/12/2013 |
Series | Lecture Notes in Computer Science |
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Volume | 8269 |
ISSN | 0302-9743 |