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Corporate InformationResearch & Development

January 16, 2013

Report from Presenter

ICISC 2012 (The 15 th International Conference on Information Security and Cryptology) was held in Seoul, Korea on November 28-30, 2012. The scope of this international conference widely covers all aspects of theory and applications of information security and cryptology. This year, 120 papers are submitted, and the conference consists of 32 oral presentations and 3 invited talks.

Yokohama Research Laboratory introduced a presentation entitled "Batch Verification Suitable for Efficiently Verifying A Limited Number of Signatures" concerning batch verification of digital signatures suitable for efficiently verifying a limited number of signatures in real-time*.

This is a joint work with Prof. Dr. Takagi at Kyushu University.

Fig. 1 Motivation

Digital signature is one of the security function which provides data integrity, ensures message and/or signer authentication, and supports non-repudiation. Digital signature uses special mathematical function such as exponentiation, scalar multiplication on an elliptic curve, and so on. Signature verification needs to compute mathematical function which is a dominant step in verification process, and sometimes it requires to verify multiple signatures efficiently. A batch verification for digital signature scheme is a method to verify multiple signatures simultaneously in order to significantly speed up signature verification.

In previous methods, it is assumed that the signed data have already stored in the storage server. Because of this assumption, previous methods are not suitable for verifying multiple signatures immediately after the server received a limited number of signatures in real-time (Fig. 1). In order to solve the issue, we proposed a new batch verification test for ECC-based signature schemes. Our proposed tests use two special families of elliptic curves which have efficiently computable endomorphisms on the curves (Fig. 2). As a result, the proposed tests are suitable for efficiently verifying a limited number of signatures (Fig. 3).

Fig. 2 Two types of elliptic curves
which are used in our new test


Fig. 3 Our new Test

(By HAKUTA Keisuke)

Related Papers

  • K. Hakuta, H. Sato, and T. Takagi, Efficient arithmetic on subfield elliptic curves over small finite fields of odd characteristic, J. Math. Cryptol. 4 (2010), No.3, 199-238.
  • K. Hakuta, H. Sato, and T. Takagi, Explicit lower bound for the length of minimal weight τ-adic expansions on Koblitz curves, J. Math-for-Ind. 2A (2010), 75-83.
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