EC OTS (onchain). Has anyone considered it?

The email delves into the concept of validating a threshold signature in Bitcoin Script without using hash-based constructions, specifically discussing a scenario where a threshold signature scheme like FROST is used in place of traditional methods. The sender explores utilizing elliptic curve scalar multiplication instead of one-way hash functions to create a verifiable and non-equivocating signature verification process within Bitcoin's scripting language.

The discussion outlines how each bit of a message could be verified in Bitcoin Script by employing an innovative technique involving R-committed keys for each bit or digit of the message. In this proposed method, for every binary value, two elliptic curve points are generated and published. These points represent possible signatures that can verify without revealing the private key unless both are revealed (equivocation), which would be penalized. This setup ensures that the signature of the actual message bit can be validated discretely within the script itself without leaking sensitive key information.

Moreover, the approach suggests moving away from hash chains, like those used in Winternitz OTS, due to their unsuitability for repeated use in this particular context. Instead, the focus shifts towards a more granular method that involves breaking down the message into smaller units (potentially using bases greater than binary, such as base 16) to be processed within the constraints of Bitcoin Script capabilities, which currently do not support elliptic curve multiplication directly.

This method's potential benefits include enhanced security through non-reveal of private keys and the ability to implement complex rule validations based on external attestations within the decentralized network of Bitcoin, using threshold signatures that cater to scenarios requiring aggregated consensus without resorting to bulky and less scalable hash-based solutions. The sender appears to propose this as a novel solution to overcome current limitations in Bitcoin Script while addressing specific use cases that demand a high level of security and scalability.