1

The original Lightning Paper required both signatures for the Breach Remedy Tx (see also this Q) but according to the BOLT #3 specs the Breach Remedy Tx only seems to hinge on the revocationpubkey for which Alice will share her revocation secret upon establishing a new Commitment Tx.

I'm wondering if I am missing some detail here.

1 Answer 1

1

You are right that in the BOLT3 Scripts the revocation path pays only to a single public key, the revocationpubkey.

In order to keep the same restriction with a single pubkey, the revocationpubkey is derived based on both a secret generated by the local node and one by the remote node.
Without the part of the secret only known to the local node, the remote node cannot spend from this path. In order to revoke a commitment, the local shares this secret to the remote node effectively allowing it to steal all the funds should it broadcast this transaction.

See the revocationpubkey derivation specification in BOLT3.

1
  • 1
    I think it is worthwhile to add that this trick works as going from private keys to public keys is done by multipling the generator point with a private key and that this process is a group homomorphism. Eg: (p+q)*G=pG+qG=P+Q where capital letters are points of the elliptic curve and lower letters are scalars in the additative group of a prime field Jul 12, 2021 at 18:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.