Article · Wikipedia archive · Last revised Jul 2, 2026

KCipher-2

KCipher-2 is a stream cipher jointly developed by Kyushu University and Japanese telecommunications company KDDI. It is standardized as ISO/IEC 18033–4, and is on the list of recommended ciphers published by the Japanese Cryptography Research and Evaluation Committees (CRYPTREC). It has a key length of 128 bits, and can encrypt and decrypt around seven to ten times faster than the Advanced Encryption Standard (AES) algorithm.

Last revised
Jul 2, 2026
Read time
≈ 1 min
Length
208 w
Citations
9
Source
Wikipedia ↗
KCipher-2
General
Designers1
First published2007 (2007)2
CertificationCRYPTREC3
Cipher detail
Key sizes128 bits2
State size640 bits2

KCipher-2 is a stream cipher jointly developed by Kyushu University and Japanese telecommunications company KDDI.4 It is standardized as ISO/IEC 18033–4,5 and is on the list of recommended ciphers published by the Japanese Cryptography Research and Evaluation Committees (CRYPTREC).6 It has a key length of 128 bits, and can encrypt and decrypt around seven to ten times faster than the Advanced Encryption Standard (AES) algorithm.4

Notes

Notes

  1. "Product Outline｜KCipher-2 | KDDI Research". www.kddi-research.jp. Archived from the original on 2026-01-22. Retrieved 2026-01-22.
  2. Kiyomoto, S.; Shin, W. (August 2013). A Description of the KCipher-2 Encryption Algorithm. IETF. doi:10.17487/RFC7008. RFC 7008.
  3. "CRYPTRECの電子政府推奨暗号、国産の「Camellia」や「KCipher-2」などリスト入り | 日経クロステック（xTECH）". 日経クロステック（xTECH） (in Japanese). 2013-03-26. Archived from the original on 2026-01-22. Retrieved 2026-01-22.
  4. Seto & Saitō 2019, p. 231.
  5. Hidaka 2012.
  6. Seto & Saitō 2019, p. 234.
References

References

  • Seto, Mitsuki; Saitō, Ken'ichi (2019). Tettei Kōryaku: Jōhō Shori Anzen Kakuho Shienshi Kyōkasho [Comprehensive Strategy: Registered Information Security Specialist Textbook] (in Japanese) (2020 ed.). Impress.
  • Hidaka, Akira (17 February 2012). "Hayai, Karui, Namae no Yurai ga Omoshiroi? Mobairu Kiki ni Tekishita Angōka Gijutsu "KCipher-2" to wa?" [Fast, Light, a Name with an Interesting Origin? About "KCipher-2", an Encryption Algorithm Suited for Mobile Devices] (in Japanese). IT Media. Retrieved 2 October 2020.