3rd International ICST Symposium on Information Assurance and Security

Research Article

Low-cost Anonymous Timed-Release Encryption

  • @INPROCEEDINGS{10.1109/IAS.2007.10,
        author={D.  Hristu-Varsakelis and  K.  Chalkias and G.  Stephanides},
        title={Low-cost Anonymous Timed-Release Encryption},
        proceedings={3rd International ICST Symposium on  Information Assurance and Security},
        keywords={bilinear pairings  cryptographic protocols  multiple time-servers.  timed-release encryption},
  • D. Hristu-Varsakelis
    K. Chalkias
    G. Stephanides
    Year: 2007
    Low-cost Anonymous Timed-Release Encryption
    DOI: 10.1109/IAS.2007.10
D. Hristu-Varsakelis1,*, K. Chalkias1,*, G. Stephanides1,*
  • 1: University of Macedonia Department of Applied Informatics Computational Systems and Software Engineering Laboratory Thessaloniki, Greece
*Contact email: dcv@uom.gr, chalkias@java.uom.gr, steph@uom.gr


We propose a new server-based efficient protocol for time-release encryption (TRE), or - as sometimes referred to - sending information "into the future". As with other recently-proposed schemes, ours is based on the use of bilinear pairings on any Gap Diffie-Hellman group, allowing absolute release time of the encrypted data. Our protocol possesses the required properties regarding user anonymity and server passivity. It also provides almost-costless scalability in settings with multiple time-servers, and improves significantly upon existing TRE schemes, in terms of computational and communication cost. This makes our approach well-suited to a number of emerging e-applications that require future decryption of confidential data.