Paper 2021/1050

Privacy-Enhancing Group Signcryption Scheme

Sara Ricci, Petr Dzurenda, Jan Hajny, and Lukas Malina


In the last decades, several signcryption schemes have been proposed for different privacy-enhancing purposes. In this paper, we propose a new privacy-enhancing group signcryption scheme that provides: unforgeability, confidentiality, ciphertext and sender anonymity, traceability, unlinkability, exculpability, coalition-resistance, and unforgeable tracing verification. It is important to notice that the proposed scheme allows a signer to anonymously signcryt a message on the group's behalf (i.e., sender's anonymity). Security analysis of the scheme is also provided. Our proposal is proven to be strongly existentially unforgeable under an adaptive chosen message attack, indistinguishable under an adaptive chosen ciphertext attack, and to provide ciphertext anonymity under an adaptive chosen ciphertext attack. Furthermore, the scheme is extended to work in a multi-receiver scenario, where an authorized group of receivers is able to unsigncrypt the ciphertext. The experimental results show that our scheme is efficient even on computationally restricted devices and can be therefore used in many IoT applications. Signcrypt protocol on smart cards takes less than 1~s (including communication overhead). The time of Unsigncrypt protocol on current ARM devices is negligible (less than 40 ms).

Available format(s)
Cryptographic protocols
Publication info
Preprint. MINOR revision.
anonymitygroup signatureselliptic curve cryptosystemimplementationsmart cardszero knowledge
Contact author(s)
ricci @ vutbr cz
2021-08-16: received
Short URL
Creative Commons Attribution


      author = {Sara Ricci and Petr Dzurenda and Jan Hajny and Lukas Malina},
      title = {Privacy-Enhancing Group Signcryption Scheme},
      howpublished = {Cryptology ePrint Archive, Paper 2021/1050},
      year = {2021},
      note = {\url{}},
      url = {}
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