12775 adds support for RapidCheck (a QuickCheck reimplementation) to Bitcoin Core, providing a property-based testing suite that generates its own tests based on what programmers tell it are the properties of a function (e.g. what it accepts as input and returns as output). ● Allocate time to test Bitcoin Core 0.17RC2: Bitcoin Core has uploaded binaries for 0.17 Release Candidate (RC) 2. Testing is greatly appreciated and can help ensure the quality of the final release. ● Library announced for BLS signatures: well-known developer Bram Cohen announced a "first draft (but fully functional) library for doing BLS signatures based on a construction based on MuSig". Still, this open source library gives developers a convenient way to begin experimenting with BLS signatures and even start to use them in applications that don’t need to be as secure as the Bitcoin network. 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 scalability-enhancing BLS signatures, and some notable commits from the Bitcoin Core, LND, and C-Lightning projects. This week’s newsletter includes a reminder to please help test the release candidate for Bitcoin Core’s next version, information about the development of Optech’s new public dashboard, summaries of two discussions on the Bitcoin-Dev mailing list, and notable commits from Bitcoin infrastructure projects.

● Discussion of arbitrary contracts over LN: youtu.be 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. 12490 removes the signrawtransaction RPC from the master development branch. This new PR removes the startup abort and simply produces a warning. Probably for a future release, a mechanism for client compatibility will be implemented and the startup abort will be restored. 13799: Prior to the first Optech newsletter, a PR was merged that deliberately caused Bitcoin Core to abort startup if the configuration file or start-up parameters contained an option Bitcoin Core didn’t recognize. Thus you have a call option (buy) and a put option (sell). This PR provides a new rule that allows payments with forwarding fees up to 50 nBTC to go through regardless of their fee percentage and adds an option so that users can customize that value. Traders aren’t particularly enthusiastic about this local US alternative to Binance because of its restricted availability, lower scale, and expensive fees.

● Transaction fees remain very low: Anyone who can wait 10 or more blocks for confirmation can reasonably pay the default minimum fee rate. Simplified Payment Verification (SPV) uses a merkle tree to prove a transaction exists in a block that itself belongs to the best block chain-the block chain with the most proof of work. The first is that there’s no known way to verify them as fast as Schnorr signatures-and signature verification speed is also important for network scalability. That is, as more miners join, or as existing miners buy more servers, or as the servers themselves get faster, the bitcoin network automatically adjusts the solution criteria so that finding those passwords requires proportionately more random guesses, and thus more computing power. Second, to prove that BLS signatures are secure requires making an additional assumption about part of the scheme being secure that isn’t required for proving the security of Bitcoin’s current scheme (ECDSA) or proposed Schnorr-based scheme. Finally, BLS signatures have only been around for about half as long as Schnorr signatures, are even less commonly used, and are not believed to have received the same amount of expert review as Schnorr signatures.

BLS signatures do come with three downsides that have lead most Bitcoin protocol developers to focus on Schnorr signatures for the short-term. In such a situation it is important to have a safe and secure Bitcoin wallet. 14096 provides documentation for output script descriptors which are used in the new scantxoutset RPC in Bitcoin Core 0.17 and are expected to be used for other interactions with the wallet in the future. 5 to add output script descriptors support to the upcoming 0.17 RPC scantxoutset has been merged. 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. A24. When you receive cryptocurrency from an airdrop following a hard fork, you will have ordinary income equal to the fair market value of the new cryptocurrency when it is received, which is when the transaction is recorded on the distributed ledger, provided you have dominion and control over the cryptocurrency so that you can transfer, sell, exchange, or otherwise dispose of the cryptocurrency. More information on the workshop will be released in a few weeks.