Privacy in Sigstore
Photo by Tim Mossholder on Unsplash By default, the keyless signing flow for Sigstore exposes a user’s email: $ rekor-cli search --email zack@example.com \ # not my real email! | wc -l Found matching entries (listed by UUID): 112 Specifically, a user logs in to Fulcio with OIDC. Fulcio issues a short-lived certificate with the SAN set to your email address as reported by the OIDC identity provider, even if your email is not typically exposed on that service itself (for instance, your GitHub email will be exposed, even though it’s not generally public).