It's time for the secondly monthly research report for my current funding period. Thanks as always to the community for its support for research.
Transaction protocol analysis continues. While the current RingCT 3.0 protocol contains an exploitable flaw, a fix is forthcoming. Its proof-of-concept code has already been updated to include a more efficient verifier and support for fees, and the code will be further updated once the fix is released. Proof-of-concept code for Lelantus has also been updated for robustness. I continue to research the applicability of new proving systems that have been released as preprints.
At this year's DEF CON event in Las Vegas, I had several roles. Besides answering many research questions, I presented a talk on transaction protocol efficiency, led a workshop on coding basic cryptographic constructions, created a cryptographic challenge puzzle, and participated in a panel.
A couple of pull requests deserve mention. One of them, PR 5807, fixes an issue where basic Schnorr signatures used a biased nonce value. Note that these signatures are not used for on-chain transaction signing. Another, PR 5707, speeds up MLSAG ring signatures by removing redundant point operations. This has been updated to simplify available hash-to-point operations. Code for CLSAG has been updated to reflect these underlying changes.
Both the CLSAG and threshold ring signature preprints are being revised in preparation for their submission for peer review. Several possible conference and journal destinations have been identified, but the review process is often quite lengthy.
Thanks to recent work by Surae Noether, code used for analyzing bipartite graph matchings is being updated and analyzed to run simulations. The results will be used to better understand the relationship between transaction operations and tracing heuristics.
And now on to Sarang's Reading Corner, a short listing of some interesting papers that I have come across this month. The appearance of a paper in this list does not mean that I necessarily agree with its contents or correctness, or that I endorse it. Papers are in no particular order.
- Bitcoin Security under Temporary Dishonest Majority
- New Efficient, Constant-Time Implementations of Falcon
- Analysis of Nakamoto Consensus
- Does "www." Mean Better Transport Layer Security?
- Traceable and linkable ring signatures, traceable range proofs and applications on regulatable privacy-preserving blockchains
- Linear Approximations of Random Functions and Permutations
- A Stealthier Partitioning Attack against Bitcoin Peer-to-Peer Network
- Security analysis of two lightweight certificateless signature schemes
- Homomorphic Encryption Standard
- Ouroboros Clepsydra: Ouroboros Praos in the Universally Composable Relative Time Model
- Efficient zero-knowledge arguments in the discrete log setting, revisited
- Security of Hedged Fiat-Shamir Signatures under Fault Attacks
- Succinct Arguments for Bilinear Group Arithmetic: Practical Structure-Preserving Cryptography