The Fintech Builder · strict Ed25519 checkpoint

A signature is one layer of the answer.

Inspect the exact checkpoint, authorized key and retained expected copy. Keep a valid signature separate from full ledger integrity and signing-time evidence.

Synthetic Cedar · public RFC test seeds only · actual bundled noble point checks and WebCrypto verification. The independent trust registry is modeled host evidence.

Changing a signed field recomputes exact C and E. Re-signing with a public demo seed repairs signature mathematics, not retained correspondence or authority.

All three checks stay visible

Checkpoint bytes signed directly, with the complete envelope hashed for an anchorPure Ed25519 signs C, which contains all eleven checkpoint fields in the authored order. The envelope E also includes the key label, algorithm and signature. SHA256 E is an anchor content digest, not proof of an external anchor.Checkpoint CsignPure Ed25519 · C itselfNo SHA256 prehash or ctx/phSHA256(E) binds payload + key label + signature

created_at is a signed assertion. It does not prove when the key actually signed, and this verifier does not inspect the source journals.

Retained-checkpoint conclusion

Envelope content digest

Authority and exact signed signature


Every checkpoint field is retained
C uses the fixed field order shown here. Object delivery order cannot change the bytes; a changed field cannot disappear from the signature.
FieldSubmitted valueIndependent expected valueSame bytes?
Full authored framing bytes C and E