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A summary of relevant action items, dashboard items, and news from the broader Bitcoin open source community. This week’s newsletter includes the usual dashboard and action items, a link to discussion about generalized Bitcoin contracts over Lightning Network, a brief description of a recently-announced library for Bitcoinxxo.com scalability-enhancing BLS signatures, and some notable commits from the Bitcoin Core, LND, and C-Lightning projects. No new action items, but follow-up related to the following previously-published items is still recommended. ● Upgrade to Bitcoin Core 0.16.1, released 15 June 2018. Upgrade especially recommended for miners. 13452: The verifytxoutproof RPC is no longer vulnerable to a particular expensive attack against SPV proofs publicly disclosed in early June. 1579: This updates the primary backend interfaces (such as bitcoind, btcd, and neutrino SPV) to be compatible with the latest (and hopefully final) version of BIP158 compact block filters as implemented in the btcd full node, btcwallet, and Neutrino light wallet. None of this mitigates the attack for actual SPV clients. This greatly simplified debugging of common errors such as typos-but it also prevented users from putting options in their bitcoin.conf that applied to clients such as bitcoin-cli.

This currently takes over an hour even on modern desktops, but users with local BIP157 filters will be able to perform the rescan much faster and still with information theoretic perfect privacy (which lightweight clients don’t have). This can allow P2P lightweight wallets to find blocks with transactions that affect their wallet much more privately than currently possible with BIP37 bloom filters. Faster rescans for Bitcoin Core’s built-in wallet. 12257, which adds an option to the wallet that causes every output paid to the same address to be spent whenever any one of those outputs is spent. These descriptors provide a comprehensive way to describe to software what output scripts you want to find, and it’s expected to be adapted over time to other parts of the Bitcoin Core API such as importprivkey, importaddress, importpubkey, importmulti, and importwallet. ● Discussion of arbitrary contracts over LN: a thread on the Lightning Network (LN) development mailing list last week described the basic principles for performing arbitrary Bitcoin contracts in a payment channel. This can provide up to a 9x speed-up over Bitcoin Core 0.16.x for cases where the new code applies and is supported by the user’s CPU.

13543: Support for the RISC-V CPU architecture added. 13386: New specialized SHA256 functions that take advantage of CPU extensions and knowledge of specific data inputs used by Bitcoin Core (such as the very common case where the input data is exactly 64 bytes, as used for every calculation in a Bitcoin merkle tree). So how does one take advantage of this? Optech has begun planning its first European workshop, which is set to take place in Paris sometime in November. Take our early coverage of Bitfinex – specifically, reporting on their precarious banking relationships – which set off a wave of attacks from trolls convinced we were paid propagandists. NOINPUT: BIP118 describes a new optional signature-hash (sighash) flag that doesn’t identify which set of bitcoins it is spending. The discussion this week on the bitcoin-dev and lightning-dev mailing lists was about naming the sighash flag so that developers don’t use it accidentally without realizing its dangers. Transaction graph analysis can identify use of a mixing service and flag the user as potentially suspicious. Instead of an independent contract that resolves to True in order to be a valid transaction, the exact same contract is included in a LN payment and must return true in order for the in-channel payment transaction to be valid.

While you can open an account and make a trade with just a password, you must have two-factor authentication (2FA) enabled to make a withdrawal. Binance does not charge fees for crypto deposits, although what you pay as a withdrawal fee depends on the cryptocurrency. The best way to handle crypto investment is to know where you are investing and what are your strategies. However, the FCA has since announced that come the new year, crypto CFDs are no longer available to UK residents. If you have the most basic type of Binance account (VIP 0), both the maker and taker fee is 0.1%. However, if you hold some BNB and pay your fees with it, both the maker and taker fees drop to 0.075% (25% off). However, the team made its platform available to users at no charge whatsoever. For almost two years, BNB had very limited utility, i.e., to get trading fee discounts and invest in ICOs on the Binance platform. We’ve moved to a new platform for distributing this week’s newsletter. ● Continuing discussion about Schnorr signatures: no faults have been identified with the proposed BIP described in last week’s newsletter, but two developers have proposed optimizations, one of which has run afoul of security considerations and another one of which will likely not be added as its minor optimization comes at the tradeoff of removing different minor optimization.