The fair exchange problem has faced for a long time the bottleneck of a required trusted third
party. The recent development of blockchains introduces a new type of party to this problem …

The privacy problem in public blockchains is a well-know challenge. Despite the robustness
and decentralisation properties of the blockchain, transaction information remains visible to …

The public blockchain lacks data confidentiality. Although a level of anonymity seems
guaranteed, it is still possible to link transactions and disclose related information. A solution …

We propose Lelantus, a new anonymous payment system which ensures both transaction
confidentiality and anonymity with small proof sizes, short verification times and without …

Zero-knowledge proofs are widely adopted in Confidential Transactions (CTs). In particular,
with these proofs, it is possible to prove the validity of transactions without revealing …

We propose new zero-knowledge proofs for efficient and post-quantum ring confidential
transaction (RingCT) protocols based on lattice assumptions in Blockchain systems. First …

We study protocols that rely on a public ledger infrastructure, concentrating on protocols for
zero-knowledge contingent payment, whose security properties combine diverse notions of …

The problem of fair exchange consists of interchanging goods between two parties that do
not trust each other. Despite known impossibility results, recent works leverage the block …

While fair exchange of goods is known to be impossible without assuming a trusted party,
smart contracts in cryptocurrencies forgo such parties by assuming trust in the currency …

We propose Bulletproofs, a new non-interactive zero-knowledge proof protocol with very
short proofs and without a trusted setup; the proof size is only logarithmic in the witness size …