A New Look at Blockchain Leader Election: Simple, Efficient, Sustainable and Post-Quantum

In this work, we study the blockchain leader election problem. The purpose of such protocols is to elect a leader who decides on the next block to be appended to the blockchain, for each block proposal round. Solutions to this problem are vital for the security of blockchain systems. We introduce an efficient blockchain leader election method...

Incentives and Cryptographic Protocols for Bitcoin-like Blockchains

Bitcoin is a widely acknowledged digital currency that is designed in a decentralized manner. The recognition of Bitcoin has introduced the notion of cryptocurrencies and, in general, blockchain technology. Blockchain, within less than a decade, has become one of the most exciting technological developments. Among several exciting use cases and...

Bitcoin-compatible virtual channels

Current permissionless cryptocurrencies such as Bitcoin suffer from a limited transaction rate and slow confirmation time, which hinders further adoption. Payment channels are one of the most promising solutions to address these problems, as they allow the parties of the channel to perform arbitrarily many payments in a peer-to-peer fashion...

Practical Exchange for Unique Digital Goods

Smart contracts can be used for the fair exchange of digital goods. A smart contract can escrow the exchange where the receiver deposits the payment, and the sender claims it by providing the goods. In the case of misbehavior, the parties provide proof on whether the received goods match the pre-agreed description or not. In general, the...

Generalized Channels from Limited Blockchain Scripts and Adaptor Signatures

Decentralized and permissionless ledgers offer an inherently low transaction rate, as a result of their consensus protocol demanding the storage of each transaction on-chain. A prominent proposal to tackle this scalability issue is to utilize off-chain protocols, where parties only need to post a limited number of transactions on-chain....

Post-quantum adaptor signatures and payment channel networks

Adaptor signatures, also known as scriptless scripts, have recently become an important tool in addressing the scalability and interoperability issues of blockchain applications such as cryptocurrencies. An adaptor signature extends a digital signature in a way that a complete signature reveals a secret based on a cryptographic condition. It...

How to profit from payments channels

Payment channel networks like Bitcoin’s Lightning network are an auspicious approach for realizing high transaction throughput and almost-instant confirmations in blockchain networks. However, the ability to successfully conduct payments in such networks relies on the willingness of participants to lock collateral in the network. In Lightning...