How to Construct Identity-Based Signatures without the Key Escrow Problem

Tsz Hon Yuen; Willy Susilo; Yi Mu

Paper 2009/421

How to Construct Identity-Based Signatures without the Key Escrow Problem

Tsz Hon Yuen, Willy Susilo, and Yi Mu

Abstract

The inherent key escrow problem is one of the main reasons for the slow adoption of identity-based cryptography. The existing solution for mitigating the key escrow problem is by adopting multiple Private Key Generators (PKGs). Recently, there was a proposal that attempted to reduce the trust of the PKG by allowing a malicious PKG to be caught if he reveals the user's identity-based secret key illegally. Nonetheless, the proposal does not consider that the PKG can simply decrypt the ciphertext instead of revealing the secret key itself (in the case of identity-based encryption schemes). The aim of this paper is to present an escrow-free identity-based signature (IBS) scheme, in which the malicious PKG will be caught if it releases a signature on behalf of the user but signed by itself. We present a formal model to capture such a scheme and provide a concrete construction.

Metadata

Available format(s): PDF PS
Category: Public-key cryptography
Publication info: Published elsewhere. This is the full version of the paper in EuroPKI 2009.
Keywords: Identity-based signature key escrow
Contact author(s): thy738 @ uow edu au
History: 2009-09-25: revised; 2009-09-01: received; See all versions
Short URL: https://ia.cr/2009/421
License: CC BY

BibTeX

@misc{cryptoeprint:2009/421,
      author = {Tsz Hon Yuen and Willy Susilo and Yi Mu},
      title = {How to Construct Identity-Based Signatures without the Key Escrow Problem},
      howpublished = {Cryptology {ePrint} Archive, Paper 2009/421},
      year = {2009},
      url = {https://eprint.iacr.org/2009/421}
}