This week’s newsletter requests help testing a Bitcoin Core release candidate, summarizes continued discussion of LN anchor outputs, and describes a proposal for allowing full nodes and lightweight clients to signal support for IP address relay. Unchained Capital, the creators of Caravan, https://youtu.be/HI7Dj2JIvjA also announced a test suite for testing hardware wallet interactions within a web browser and Trezor multisig address confirmation. This will avoid wasting bandwidth on clients that don’t want the addresses and can make it easier to determine the consequences of certain network behavior related to address relay. These are often much easier to use, but you have to trust the provider (host) to maintain high levels of security to protect your coins. This makes it easier for applications to ensure they’re compatible with the currently running LND version. With multipath payments, LND can now split invoices into smaller HTLCs which can each take a different route, making better use of the liquidity in LN. ● Lightning Labs announces Faraday for channel management: Faraday is a tool for LND node operators that analyzes existing channels and makes recommendations to close problematic or under-performing channels. Whether both the party unilaterally closing the channel (the "local" party) and the other party ("remote") should experience the same delay before being able to claim their funds, or whether they should each be able to negotiate during the channel creation process for the delay duration to use when they’re the remote party.

For example, a taker can choose the amounts of the coinjoin they want to create or can spend their money to a third party as part of a coinjoin. ● Wasabi uses a centralized coordinator who organizes every coinjoin made using that software. The coordinator uses this specified value to verify that the sum of the outputs the client wants to create is equal to the sum of the inputs provided by the client (minus fees). ● BTCPay adds support for sending and receiving payjoined payments: payjoin is a protocol that increases the privacy of Bitcoin payments by including inputs from both the spender and the receiver in an onchain transaction. ● Bitpay’s Copay and Bitcore projects support native segwit: Bitpay’s Copay wallet and backend Bitcore service both now support receiving to, and spending from, native segwit outputs. 3623 adds a minimal implementation (only available with the configuration parameter --enable-experimental-features) for spending payments using blinded paths.

It’s worth noting that every transaction is tracked and can be used to reconstruct a given wallet’s spending. These dynamics can sometimes be unpredictable, and it’s impossible to list all the factors that contribute to Bitcoin price movements. It’s a saver’s platform, in other words, rather than a trader’s platform. Today, the exchange platform has registered over 15 million users, with its average daily trading volume hitting over $2 billion. Crypto heist: last August, a hacker stole $600m in a cyber attack targeting the crypto platform Poly Network, only to return more than half of it four days later saying they did it "for fun" and to "expose the vulnerability" in the system before others did. 93 for more details on this proposal. Because the coordinator is unable to view the output at the time it creates its blinded signature, it can’t allow a user to specify an arbitrary amount or the user could attempt to receive more money than they contributed to the coinjoin. ● WabiSabi coordinated coinjoins with arbitrary output values: in the coinjoin protocol, a group of users collaboratively create a transaction template that spends some of their existing UTXOs (inputs) to a new set of UTXOs (outputs).

● Joinmarket has two types of users: those who pay to coinjoin (market takers) and those who are paid for allowing their UTXOs to be used (market makers). To create a coinjoin, takers contact several makers, collect their input and output information, and create the transaction template. This allows constructing the transaction template without the coordinator learning which inputs funded which outputs. To prevent that coordinator from learning which inputs fund which outputs, users anonymously commit to the outputs they want to create, receiving a chaumian blinded signature over the commitment. 3967 adds support for sending multipath payments, complementing the already-existing receiving logic. For this change to have the maximum impact, other popular wallets need to implement support for creating compatible payjoin payments. This week’s newsletter summarizes a proposal for creating a unified multi-wallet backup that circumvents the inability to import BIP32 extended private keys into many wallets that support deterministic key derivation. 910 Assigns BIP85 to Ethan Kosakovsky’s Deterministic Entropy From BIP32 Keychains proposal. ● Proposal for using one BIP32 keychain to seed multiple child keychains: several weeks ago, Ethan Kosakovsky posted to the Bitcoin-Dev mailing list a proposal for using one BIP32 Hierarchical Deterministic (HD) keychain to create seeds for child HD keychains that can be used in different contexts.