Author: Jim Posen 2018-05-08 15:54:58
Published on: 2018-05-08T15:54:58+00:00
The discussion on the deployment of scriptless scripts on lightning continues with arguments against making certain protocol changes to the base Bitcoin blockchain for the reason that they may not be quantum resistant. The worst-case scenario is much worse in case of Confidential Transactions as an attacker could print money freely and without detection, compromising the fundamental security of the blockchain. In contrast, the attack scenario on scriptless scripts is that a peer is going to use a quantum computer to steal all live payments routed through them from their senders before they get to the recipient, which would be bad but not catastrophic. Once it is recognized that the attack is possible, insecure channels could be closed. However, Benjamin Mord notes that the scriptless scripts concept (as currently formulated) falls to Schor's algorithm, and at present there is no alternative implementation of the concept to fall back on. He urges everyone to not depend on functional concepts whose underlying cryptographic primitives cannot be swapped in an emergency. Although ecdsa is also vulnerable to Schor's algorithm, in contrast to scriptless scripts we have a variety of backup primitives at our disposal that fulfill the same functional objective. Therefore, adding some cryptographic conservatism before building on the functional concept of scriptless scripts is necessary. Mord points out that Lattice-based cryptography is a Shor's algorithm-resistant scheme, but there are not a variety of post-quantum schemes, except perhaps in contexts where time can be used for asymmetry, as in TESLA, where hash functions can create something like asymmetric signatures. However, the functional context has to be compatible with delayed verification. He believes that redundancy of any sort is good, even when not focused specifically on quantum risks, since the history of even pre-quantum cryptanalysis shows that primitives tend to have finite lifespan.
Updated on: 2023-05-24T23:31:19.378272+00:00