English

The Joint Signature and Encryption Revisited

Cryptography and Security 2016-11-01 v1

Abstract

We study the Sign_then_Encrypt, Commit_then_Encrypt_and_Sign, and Encrypt_then_Sign paradigms in the context of two cryptographic primitives, namely designated confirmer signatures and signcryption. Our study identifies weaknesses in those paradigms which impose the use of expensive encryption (as a building block) in order to meet a reasonable security level. Next, we propose some optimizations which annihilate the found weaknesses and allow consequently cheap encryption without compromising the overall security. Our optimizations further enjoy verifiability, a property profoundly needed in many real-life applications of the studied primitives.

Keywords

Cite

@article{arxiv.1610.09503,
  title  = {The Joint Signature and Encryption Revisited},
  author = {Laila El Aimani},
  journal= {arXiv preprint arXiv:1610.09503},
  year   = {2016}
}

Comments

70 pages

R2 v1 2026-06-22T16:36:11.540Z