Cryptology ePrint Archive: Report 2009/143

Multiple and Unlinkable Public Key Encryption without Certificates

Soyoung Park and Sang-Ho Lee and Joohan Lee

Abstract: We newly propose a multiple and unlinkable identity-based public key encryption scheme. Unlike the traditional public key encryption and identity-based encryption schemes, our scheme allows the use of a various number of identity-based public keys in different groups or applications while keeping a single decryption key so that the decryption key can decrypt every ciphertexts encrypted with those public keys. Also our scheme removes the use of certificates as well as the key escrow problem so it is functional and practical. Since our public keys are unlinkable, the user's privacy can be protected from attackers who collect and trace the user information and behavior using the known public keys. Furthermore, we suggest a decryption key renewal protocol to strengthen the security of the single decryption key. Finally, we prove the security of our scheme against the adaptive chosen-ciphertext attack under the random oracle model.

Category / Keywords: public-key cryptography / elliptic curve cryptosystem, public key cryptosystem

Date: received 27 Mar 2009

Contact author: soyoung5002 at gmail com

Available format(s): PDF | BibTeX Citation

Version: 20090331:024911 (All versions of this report)

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