ESSPI: ECDSA / Schnorr Signed Program Input for BitVMX

In this paper, we introduce a novel approach to signing BitVMX program inputs using ECDSA or Schnorr signatures, replacing the traditional one-time signature (OTS) scheme.

This advancement significantly improves efficiency, achieving a 1:1 data expansion factor compared to the 1:200 ratio of Winternitz signatures. Our method enables the verification of uncompressed SPV proofs, STARKs, NOVA, and Bulletproofs, broadening the applicability of BitVMX.

To verify Schnorr/Winternitz signature equivalence and safeguard against malformed or fraudulent data publications, we incorporate a secondary BitVMX instance. Furthermore, we integrate a SHA-256 hasher into the BitVMX CPU to hash and verify unsigned program input.

Our most advanced scheme, based on enveloping, seamlessly integrates with standard Bitcoin transactions, ensuring minimal overhead while maintaining security and scalability.

Find out more about this significant milestone by accessing the paper here.