A key escrow system of the RSA cryptosystem

  • Yoshiki Sameshima
Key Management
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1396)


This paper focuses a key escrow system of the RSA cryptosystem that protects user privacy with the following properties; (1) neither investigation agency nor key escrow agent accesses private key of user directly, (2) investigation agency can decrypt user data of restricted time period and communication entities, and (3) split private keys of user are deposited correctly in multiple key escrow agents without any information leakage of the private key with help of a zero-knowledge interactive protocol. The security of the whole system is discussed as well as the performance of the zero-knowledge interactive protocol.


Data Encryption Target User Average Response Time Encrypt Data Investigative Agency 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    C.Boyd, “Some Applications of Multiple Key Ciphers,” Advances in Cryptology: Proceedings of Crypto 88, Springer-Verlag, pp. 455–467 (1989)Google Scholar
  2. 2.
    W.Diffie and M.Hellman, “New Directions in Cryptography,” IEEE Transactions of Information Theory, 22 pp. 644–654 (1976)Google Scholar
  3. 3.
    R.ElGamal, “A public key cryptosystem and a signature scheme based on discrete logarithms,” IEEE Transactions on Information Theory, 31, pp.469–472 (1985)Google Scholar
  4. 4.
    A.Fiat and A.Shamir, “How To Prove Yourself: Practical Solutions to Identification and Signature Problems,” Advances in Cryptology: Proceedings of Crypto 86, Springer-Verlag, pp. 186–194 (1987)Google Scholar
  5. 5.
    A.K.Lenstra, P.Winkler and Y.Yacobi, “A Key Escrow System with Warrant Bounds,” Advances in Cryptology: Proceedings of CRYPTO'95, Springer-Verlag, pp. 197–207 (1995)Google Scholar
  6. 6.
    S.Micali, “Fair Public-Key Cryptosystems,” Advances in Cryptology: Proceedings of CRYPTO'92, Springer-Verlag, pp. 113–138 (1992)Google Scholar
  7. 7.
    OrganizationforEconomicCo-operationandDevelopment, “OECD Adopts Guidelines for Cryptography Policy,” ( (March 1997)Google Scholar
  8. 8.
    R.L.Rivest, A.Shamir and L.Adleman, “A method for obtaining digital signatures and public key cryptosystems,” Communications of ACM, 21, pp. 120–126 (1978)Google Scholar
  9. 9.
    B.Schneier, Applied Cryptography, Second Edition, John Wiley & Sons, Inc. (1996)Google Scholar
  10. 10.
    I.Taylor (MBE MP Minister for Science & Technology), “Licensing of Trusted Third Parties for the Provision of Encryption Services,” Public Consultation Paper on Detailed Proposals for Legislation ( (March 1997)Google Scholar
  11. 11.
    The White House, Office of the Press Secretary, “Statement by the Press Secretary,” ( /Key-esc:row/CIipl>er_Capstone_EES-I'essera Skipjack/wh_c.ryl)to-original.attnouoce) (16th April 1993)Google Scholar
  12. 12.
    Y.Yamane and K.Sakurai, “How to restrict investigators' tapping in Key Escrow Systems,” (in Japanese) The 1996 Symposium on Cryptography and Information Security 7C, The Institute of Electronics, Information and Communication Engineers (January 1996)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Yoshiki Sameshima
    • 1
  1. 1.R & D DepartmentHitachi Software Engineering Co., Ltd.YokohamaJapan

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