Paper 2010/070

Strongly Unforgeable Signatures and Hierarchical Identity-based Signatures from Lattices without Random Oracles

Markus Rückert


We propose a variant of Peikert's lattice-based existentially unforgeable signature scheme in the standard model. Our construction offers the same efficiency as Peikert's but supports the stronger notion of strong unforgeability. Strong unforgeability demands that the adversary is unable to produce a new message-signature pair (m, s), even if he or she is allowed to see a different signature sig' for m. In particular, we provide the first treeless signature scheme that supports strong unforgeability for the post-quantum era in the standard model. Moreover, we show how to directly implement identity-based, and even hierarchical identity-based, signatures (IBS) in the same strong security model without random oracles. An additional advantage of this direct approach over the usual generic conversion of hierarchical identity-based encryption to IBS is that we can exploit the efficiency of ideal lattices without significantly harming security. We equip all constructions with strong security proofs based on mild worst-case assumptions on lattices and we also propose concrete security parameters.

Note: Full version.

Available format(s)
Public-key cryptography
Publication info
Published elsewhere. PQCrypto 2010
Post-quantum cryptographylattice cryptographydigital signaturesidentity-based cryptographystandard model
Contact author(s)
rueckert @ cdc informatik tu-darmstadt de
2010-03-01: revised
2010-02-11: received
See all versions
Short URL
Creative Commons Attribution


      author = {Markus Rückert},
      title = {Strongly Unforgeable Signatures and Hierarchical Identity-based Signatures from Lattices without Random Oracles},
      howpublished = {Cryptology ePrint Archive, Paper 2010/070},
      year = {2010},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.