The Bitcoin Diaries

On 29 November 2013, the cost of one bitcoin rose to a peak of US$1,242. 0: partial spend avoidance is used whenever the maximum additional cost it adds to the transaction is the passed amount. Whichever result is cheaper is used; if they both result in the same cost, partial spend avoidance is used. 19743 add a new maxapsfee ("max avoid partial spends fee") configuration option to specify the maximum amount of extra fee you’re willing to pay to avoid partial spends when the existing avoidpartialspends configuration option is disabled. 0 (the default value): fee calculations are made using both coin selection algorithms. This feature was requested to help improve integration between BTCPay Server’s default hot wallet and the optional LN server. 4171 updates the hsmtool command with a new dumponchaindescriptors parameter that prints the output script descriptors for the keys and scripts used by C-Lightning’s onchain wallet. 955 updates BIP174 to standardize supplying hash preimages in PSBT input records. 3954 updates both the fundpsbt and utxopsbt RPCs so that they can each take a locktime parameter that specifies the nLockTime of the transaction to create.

Because anyone who was ever a delegate can trigger an onchain spend, statechains are designed to use the eltoo mechanism to ensure an onchain spend by the most recent delegate (Carol) can take precedence over spends by previous delegates (Alice and Bob), assuming the trusted third party hasn’t colluded with a previous delegate to cheat. This can be a major problem for protocols like LN that rely on timelocks-if a transaction isn’t confirmed before the timelock expires, the counterparty can take back some or all of the funds they previously paid. 1599 makes spending more intelligent when considering sending a multipath payment to a channel counterparty. ● Implementing statechains without schnorr or eltoo: statechains are a proposed offchain system for allowing a user (such as Alice) to delegate the ability to spend a UTXO to another user (Bob), who can then further delegate the spending authority to a third user (Carol), etc. The offchain delegation operations are all performed with the cooperation of a trusted third party who can only steal funds if they collude with a delegated signer (such as previous delegates Alice or Bob). 6), but it may result in slightly higher fees due to spending all inputs received to the same address when only a subset of those inputs might be needed.

In practice, LN nodes using anchor outputs should normally pay lower fees because there’s no longer any incentive to overestimate fees. 808 adds a warning that nodes must not release their own HTLC preimages unless they’re the final receiver of a payment. 4168 adds the ability for a plugin to specify that a hook be run before or after that of another plugin. 88), Karl-Johan Alm has proposed a simplification that removes the ability to bundle together several signed messages for different scripts and also removes an unused abstraction that could’ve made it easier to extend the protocol for something similar to BIP127 proof of reserves. This week’s newsletter describes a proposal to make statechains deployable on Bitcoin without consensus changes, summarizes a discussion about a schnorr nonce generation function that helps protect against differential power analysis, and links to a proposed update to BIP322 generic signmessage. BIP340 co-author https://youtu.be/ Pieter Wuille replied with an explanation: in key and signature aggregation where a mathematical relationship is created between the private keys of cooperating users, the attacker-if he’s one of the cooperating users-may be able to combine knowledge of his private key with information learned from power analysis of other users’ signature generation in order to learn about the other users’ private keys.

Replace the 2-of-2 schnorr multisig between the trusted third party and the current delegate (using an adaptor signature) with a single-sig using secure multiparty computation. Murch provides an overview of the effective value approach to coin selection, consideration of change avoidance, and attention to signature length. Anyone with feedback on the change is encouraged to either reply to the mailing list thread or to the PR updating the draft BIP. Many blockchain networks operate as public databases, meaning anyone with an internet connection can view a list of the network’s transaction history. Gas fees refer to payments made to crypto miners whose computing power processes transactions on the blockchain. It is believed that this attack would be easier to execute when looking at the power consumption of a relatively complex hash function like SHA256 compared to a relatively trivial function like xor (binary addition). A power analysis attack involves monitoring the amount of electricity a hardware wallet uses when it generates different signatures in order to potentially learn what private key was used (or to reveal enough information about the key that effective brute forcing becomes possible). Fournier questioned the utility of combining the private key plus the randomness using an xor operation rather than a more standard method of hashing the private key with the randomness.