Paper 2026/779

And TLS lived happily ever after

Gora Adj, Technology Innovation Institute

Francisco Rodríguez-Henríquez, Technology Innovation Institute

Abstract

The plausible threat of a Cryptographically Relevant Quantum Computer (CRQC) has rightly stimulated a move away from traditional methods of asymmetric cryptography to new post-quantum secure equivalents. Digital signature is the cryptographic primitive that authenticates an internet server’s identity by signing each certificate in an X.509 certificate chain. A suggested response to the CRQC threat is to deploy a hybrid classical/post-quantum digital signature, combining a traditional tried-and-tested scheme with a post-quantum alternative, where certificates are signed using both methods. Here we propose a fused signature scheme that adopts the same approach, but introduces minimal friction into existing TLS architectures

@misc{cryptoeprint:2026/779,
      author = {Michael Scott and Gora Adj and Francisco Rodríguez-Henríquez},
      title = {And {TLS} lived happily ever after},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/779},
      year = {2026},
      url = {https://eprint.iacr.org/2026/779}
}