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.
News
Fireblocks raises $550M at $8B Valuation. [Link]
Diem to sell assets to Silvergate Bank for $200M. [Link]
Phantom’s $109M Series B. [Link]
Trezor adopts the Swiss Travel rule and then removes support following backlash from the community. [Link]
I’m not familiar with the details of the Swiss Travel rule, but the Address Ownership Proof Protocol (AOPP) outlines the specification. [Link]
Trezor backtracks support. [Link]
Several other wallets initially part of AOPP decided to remove support in their next releases. [Link]
NBitcoin (.NET Bitcoin implementation) decided to remove message signing (used in AOPP). I at least found this functionality useful for auditing P2PKH scripts. [Link]
Robinhood begins rolling out support for wallets. [Link]
Bitcoin
Jameson Lopp’s Bitcoin 2021 Annual Review. [Link]
BOLT 11: How to Pay People on Lightning. [Link]
This Week in Lightning video series. [Link]
Adam Gibson publishes PathCoin. [Link]
Sparrow Wallet tests indexing performance of Electrum servers. [Link]
Bitcoin Core does not provide an index on scripts, therefore it is the responsibility of the wallet developer to build an index in order to query for balances and help with wallet rescanning.
They identify Fulcrum as an alternative to Electrs for faster querying with the trade-off of more disk space. [Link]
What Peer Announcements Tell Us About the Size of the Bitcoin P2P Network. [Link]
Analysis and Probing of Parallel Channels in the Lightning Network. [Link]
Resurrecting Address Clustering in Bitcoin. [Link]
Bitcoin Core 23.0 will have Apple Silicon binaries. [Link]
Connecting Blockchain Data with LDK. [Link]
Ethereum
Reddit user asks: “Did I just lose half a million dollars by sending WETH to WETH's contract address?” [Link]
Cancel Your Old OpenSea Listings. [Link]
Immunefi pushes a tutorial on securing a wallet and avoiding front-running using FlashBots. [Link]
MyCrypto is Joining MetaMask. [Link]
A list of open problems in DeFi. [Link]
Other Networks
Solana Pay. [Link]
Circle will be using Solana Pay for USDC settlement. [Link]
Shielded staking on Cosmos. [Link]
Starkware resource guide. [Link]
Crypto
Bitcoin-flavored cryptography challenges. [Link]
Threshold spending policies with Merkle trees and MuSig. [Link]
On How Zero-Knowledge Proof Blockchain Mixers Improve, and Worsen User Privacy. [Link]
Security
NFC and Coldcard Mk4. [Link]
UEFI firmware vulnerabilities affect at least 25 computer vendors. [Link]
Open Source Security Foundation announces $10 million in funding. [Link]
Releases
Releases is a new section that includes newly tagged releases for popular node implementations from the trailing week. Let me know if there is anything you want to track.
[Celo] Celo-Blockchain Release 1.5.1-stable [Link]
[LND] lnd v0.14.2-beta.rc1 [Link]
[Near] 1.24.0-rc.2 [Link]
[Polkadot] v0.9.16-rc9 [Link]
[Mina] Devnet Pre-release 1.3.0alpha3 [Link]
[Cosmos SDK] v0.46.0-alpha2 [Link]
[Filecoin] v1.14.0-rc5 [Link]
Thanks for reading! Have a great week.