Workshop survey


Credit: fiatjaf

NOSTR is a minimalistic message relay protocol, designed with social media in mind. There is a specific message schema. Each message is associated with a public key and signed.

Vulnerabilities in Threema

This work identifies a number of weaknesses in Threema (Swiss security-oriented messaging app) under several threat models.


Credit: James O’Bierne

This introduces a pair of opcodes specifically designed to support the vault workflow. This is a good example of a very narrowly conceived covenant.

Zero-knowledge proof systems

Currently, the only way to guarantee the correctness of the UTXO set is to find the most-work chain, download all the blocks, verify that each block is valid and compute the UTXO set. This is difficult or impossible for bandwidth-restricted users and creates an ongoing requirement that some users serve historical blocks.


ZeroSync is an ambitious project to use the STARK proof system to generate succinct proofs of important propositions about the bitcoin UTXO set. The goal is to make it possible for light clients to store a very small cryptographic witness as to the correctness of the UTXO set at each tip. With each block, such a client would download a new proof and verify correctness using just the old proof and the new block.


Credit: Thaddeus Dryja

Utreexo is a compact representation of the UTXO set, which supports short inclusion proofs and efficient insertion/deletion.

Window into full RBF rollout

Credit: 0xb10c

Use this tool to view transactions which do not signal RBF for which there is a double spend with a higher fee.

More flexible UTXOs for mobile users

Credit: Jesse Posner, ZmnSCPxj

Users with an LSP can receive funds to a simple contract in order to make it possible to safely spend funds via LN as soon as the onchain tx confirms. This cuts out the step of creating a new channel or doing a submarine swap, but adds a griefing vector in case the LSP becomes uncooperative.