Paper 2007/135

Efficient ID-based Signature Without Trusted PKG

Jingwei Liu, Rong Sun, Weidong Kou, and Xinmei Wang


In this paper, we introduce the exact concept of ID-based signature without trusted Private Key Generator (PKG), which solves the key escrow problem through binding two partially public keys with a same identity. In this scheme, PKG is prevented from forging a legal user’s signature because he only generates the partially private key. Using Gap Diffie-Hellman (GDH) groups, we construct an efficient ID-based signature scheme without trusted PKG, which security relies on the hardness of the Computation Diffie-Hellman Problem (CDHP). More precisely, under the random oracle model, our scheme is proved to be secure against existential forgery on adaptively chosen message and ID attack, which is a natural ID-based version of the standard adaptively chosen message attack, assuming CDHP is intractable. Our scheme not only eliminates the inherent key escrow problem but also has a higher efficiency than the existing schemes.

Available format(s)
Public-key cryptography
Publication info
Published elsewhere. has NOT been published elsewhere
ID-based SignatureKey EscrowGap Diffie-Hellman GroupBilinear PairingDishonest PKG
Contact author(s)
jwliu @ mail xidian edu cn
2007-04-18: received
Short URL
Creative Commons Attribution


      author = {Jingwei Liu and Rong Sun and Weidong Kou and Xinmei Wang},
      title = {Efficient {ID}-based Signature Without Trusted {PKG}},
      howpublished = {Cryptology ePrint Archive, Paper 2007/135},
      year = {2007},
      note = {\url{}},
      url = {}
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