Compressed XTR

Masaaki Shirase, Dong Guk Han, Yasushi Hibino, Ho Won Kim, Tsuyoshi Takagi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)


XTR public key system was introduced at Crypto 2000, which is based on a method to present elements of a subgroup of a multiplicative group of a finite field. Its application in cryptographic protocols leads to substantial savings both in communication and computational overhead without compromising security. It was shown how the use of finite extension fields and subgroups can be combined in such a way that the number of bits to be exchanged is reduced by a factor 3. In this paper we show how to more compress the communication overhead. The compressed XTR leads to a factor 6 reduction in the representation size compared to the traditional representation and achieves as twice compactness as XTR. The computational overhead of it is a little worse than that of XTR, however the compressed XTR requires only about additional 6% computational effort. If finding 4-th roots of unity is pre-computed, then the computational overhead is only 1% compared to that of original XTR. Furthermore, the required size of public key data of it reduces about 26% from that of XTR.

Original languageEnglish
Title of host publicationApplied Cryptography and Network Security - 5th International Conference, ACNS 2007, Proceedings
PublisherSpringer Verlag
Number of pages12
ISBN (Print)9783540727378
Publication statusPublished - 2007
Externally publishedYes
Event5th International Conference on Applied Cryptography and Network Security, ACNS 2007 - Zhuhai, China
Duration: Jun 5 2007Jun 8 2007

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume4521 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other5th International Conference on Applied Cryptography and Network Security, ACNS 2007

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • General Computer Science


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