This Week in Custody is a newsletter covering technical and narrative developments in digital asset custody written for wallet engineers, digital asset operators, and security engineers.
Hope everyone had a great extended weekend!
News
10 million MAU for MetaMask. Huge milestone for MetaMask as it surpasses 10 million monthly active users.
El Salvador. The anticipated government-owned Chivo Wallet launched in El Salvador this morning. There is evidence that multinational companies like McDonalds have adopted the Lightning Network. There’s not much coverage on the architecture of the wallet or its custodian other than a few leaked unconfirmed tweets.
Bitcoin
Reproducible builds. Andrew Chow has organized a website to track the reproducible builds of hardware wallet signers.
Proof of Reserves. BitMEX open sources its Proof of Reserves (PoR) and Proof of Liabilities (PoL) tool. Running the script lets you attest to the UTXO balances owned by BitMEX.
Tracing Bitcoin. 0xB10C shares his work on userspace, statically defined tracing for Bitcoin Core.
nSequence Anti-Fee Sniping. Chris Belcher proposes using the nSequence field in taproot outputs in order to obfuscate transactions relating to off-chain protocols.
Ethereum
TimeLock. Last week we covered a timelock vulnerability in the OpenZeppelin contracts. Here’s an update with a post-mortem.
Token Holdings. Etherscan launches a token holdings page that can display LP tokens held for DEXs.
ERC-1155. Etherscan also adds support for ERC-1155 tokens.
Other Chains
Polkadot Multisig. There’s a new multi-signature management tool released by Subscan.
Polkadot Telemetry. An excellent overview on telemetry tools compatible with Kusama and Polkadot daemons.
Security
Military Cryptanalytics. A 44-year old cryptanalysis book has been mostly declassified by the NSA. It’s very fascinating that it takes the agency this long to release a seemingly outdated book.
List of DeFi Security Issues. Halborn shares a list of the top DeFi and Blockchain security issues.
Thanks for reading. Have a great week!