Secure signatures without a private key

Reproducible builds allow anyone to verify that a binary matches its source code. But what if the build artifact must contain a cryptographic signature? Reproducing the signature requires the private key, which defeats the purpose of reproducibility. In this post, we present a technique based on ECDSA public key recovery that produces signatures which are both secure and fully reproducible, without anyone ever knowing a private key. Build artifacts with signatures - a reproducibility issue Remote attestation is a fundamental part of Confidential Computing. It can be used to prove what software is running in a remote environment. Users of such an attested environment do not need to trust the software vendor, excluding them from the trusted computing base1. ...

April 29, 2026 · Paul Meyer, Leonard Cohnen