This Week in Blockchain Research Issue #81

Issue #81

Issue #81

Paper of the Week:

Paper Title: Post-Quantum Adaptor Signature for Privacy-Preserving Off-Chain Payments.


  1. Adaptor signatures (AS) are an extension of digital signatures that enable the encoding of a cryptographic hard problem (e.g., discrete logarithm) within the signature itself.

  2. An AS scheme ensures that (i) the signature can be created only by the user knowing the solution to the cryptographic problem; (ii) the signature reveals the solution itself; (iii) the signature can be verified with the standard verification algorithm.

  3. These properties have made AS a salient building block for many blockchain applications, in particular, off-chain payment systems such as payment-channel networks, payment-channel hubs, atomic swaps or discrete log contracts.

  4. Current AS constructions, however, are not secure against adversaries with access to a quantum computer.

  5. This work presents IAS, a construction for adaptor signatures that relies on standard cryptographic assumptions for isogenies, and builds upon the isogeny-based signature scheme CSI-FiSh.

  6. The security of IAS is formally proven against a quantum adversary.

  7. It is implemented and our evaluated showing that IAS can be incorporated into current blockchains while requiring ∼ 1500 bytes of storage size on-chain and ∼140 milliseconds for digital signature verification.

  8. It is also shown how IAS can be seamlessly leveraged to build post-quantum off-chain payment applications such as payment-channel networks without harming their security and privacy.

AuthorsErkan Tairi*, Pedro Moreno-Sanchez†, and Matteo Maffei*,

Affiliations: * TU Wien and † IMDEA Software Institute.


1. Paper Title: Improving Bitcoin Transaction Propagation by Leveraging Unreachable Nodes.

Summary: This paper shows how unreachable nodes are often overlooked despite being a relevant part of the Bitcoin network.

Authors: Federico Franzoni* and Vanesa Daza*,

Affiliations* Universitat Pompeu Fabra.


1. Paper Title: SodsMPC: FSM based Anonymous and Private Quantum-safe Smart Contracts.

Summary: An efficient smart contract system protecting business logic privacy, data privacy, and user anonymity simultaneously.

AuthorsShlomi Dolev* and Ziyu Wang†,

Affiliations: * Ben-Gurion University of the Negev and † Beihang University.

2. Paper Title: Towards Understanding and Demystifying Bitcoin Mixing Services.

Summary: A method to further demystify mixing services that apply obfuscating mechanism by identifying mixing transactions.

Authors: Lei Wu*, Yufeng Hu*, Yajin Zhou*, Haoyu Wang†, Xiapu Luo‡, Zhi Wang§, Fan Zhang*, and Kui Ren*

Affiliations* Zhejiang University, † Beijing University of Posts and Telecommunications, ‡ The Hong Kong Polytechnic University, and § Florida State University.


1. Paper Title: Low Latency Cross-Shard Transactions in Coded Blockchain.

Summary: The use of coded computation from Polyshard to obtain higher throughout, and comparable levels of decentralization and security guarantees with respect to uncoded (i.e., ordinary) blockchain.

Authors: Canran Wang* and Netanel Raviv*,

Affiliations* Washington University in St. Louis.


1. Paper Title: Quarks: Quadruple-efficient transparent zkSNARKs.

Summary: New transparent zero-knowledge succinct non-interactive arguments of knowledge (zkSNARKs) for R1CS that do not require a trusted setup, and their security relies on the standard SXDH problem.

Authors: Srinath Setty* and Jonathan Lee*,

Affiliations* Microsoft Research.


1. Paper Title: Reducing Round Complexity of Byzantine Broadcast.

Summary: A Byzantine Broadcast protocol with expected 8 rounds under a static adversary and expected 10 rounds under an adaptive adversary.

Authors: Linda Chen* and Jun Wan*,

Affiliations* undisclosed.

2. Paper Title: Lattice-Based Proof-of-Work for Post-Quantum Blockchains.

Summary: A step towards a fuller understanding of post quantum blockchains by proposing a PoW protocol for which quantum machines have a smaller asymptotic advantage.

AuthorsRouzbeh Behnia*, Eamonn W. Postlethwaite†, Muslum Ozgur Ozmen‡, and Attila Altay Yavuz*,

Affiliations: * University of South Florida, † University of London, and ‡ Purdue University.


1. Paper Title: Costs of an Attack Against Proof-of-Work.

Summary: The expected time for the attacker to mine a secret fork, the underlying cumulative distribution function, and some related optimization problems.

AuthorsLoïc Etienne*,

Affiliations: * PwC Zürich.

2. Paper Title: How to Not Get Caught When You Launder Money on Blockchain?

Summary: A few select strategies can make money laundering on blockchain virtually undetectable with most of the currently existing tools and algorithms

Authors: Cuneyt G. Akcora*, Sudhanva Purusotham†, Yulia R. Gel†, Mitchell Krawiec-Thayer‡, Murat Kantarcioglu†,

Affiliations* University of Manitoba, † UT Dallas, and ‡ Monero Research Lab.

3. Paper Title: Rise of the Central Bank Digital Currencies: Drivers, Approaches and Technologies.

Summary: This paper has examines the rise of central bank digital currencies, a new payment technology that may soon be available in a number of countries around the world.

Authors: Raphael Auer*, Giulio Cornelli*, and Jon Frost*,

Affiliations* Bank for International Settlements.

Conferences, Journals, & CFPs:

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