Feed for category: blockchain
Mast and Schnorr Signatures
Bitcoin’s development effort for the past few years has been focused on a few key concepts, privacy, scalability and efficiency. One of the first improvements was Segregated witness which is ushering in the rest, Lightning Network followed but was an effort in a different direction as it took transactions off-chain rather than optimizing the on-chain process. Some of the upcoming technologies aimed at optimizing this process are Schnorr Signatures and Merkelized Abstract Syntax Trees or MAST for short.
A summary of the HoneyBadger conference
The Baltic Honeybadger conference is the first major event in Latvia dedicated to Bitcoin and the technologies built around it. This year’s second edition panelists included major Bitcoin developers like Brian bishop, Matt Corallo and Eric Voskuil, Cryptography specialists like Adam Back and Peter Todd, CEOs like Elizabeth Stark and Eric Lombrozo and many others. Here’s a summary of the two-day panels …
Selfish Mining Prevention

Andrew Karamaoun proposed an idea to discourage selfish mining, which is to allow the block reward get determined by the peak hash rate.

For instance if $$p$$ is the peak hash rate for 365 periods or 1 year, made up of 144 blocks, $$h$$ the hash rate of the last 144 blocks (1 day period), and $$r$$ the base subsidy or reward for mining a block, which is currently 12.5 bitcoin, the maximum block reward can then be calculated using the formula $$0.5r (1 + h/p)$$ , the lowest possible block reward being $$0.5r$$ . At peak hashrate, the miner gets the full 12.5 BTC reward, otherwise the reward is determined based on the hashrate.

Bustapay: a practical sender/receiver coinjoin protocol

One of the main features intended for Bitcoin in the future is a native support for multisig payments and coinjoins, they are currently supported by the Blockchain but not in a native way and as such they do not have as much efficiency and privacy as desired. This is going to be the main focus of the next major update in Bitcoin, changing the signature scheme to Schnorr Signatures.

As a simplified alternative to Pay-to-Endpoint (P2EP - Pay-to-Endpoint), developer Ryan Havar proposed a BIP for a new coinjoins protocol that does not need changes to the current Bitcoin consensus and provides a simple, practical way to make coinjoin transactions that are indistinguishable from normal ones.

Guiding Transaction Fees Towards a more Censorship Resistant Outcome

This is summary for a submission by Ruben Somsen on bitcoin-dev on censorship resistant transactions.

Bitcoin transactions with light client wallets involve addition of transaction fees as incentive for miners to include the transaction to the blockchain through the process of mining. This creates a win-win situation.

First, without any specific conditions, miners get paid the fees provided the transaction gets included in a valid chain with the most proof-of-work.

Secondly, the user enjoys the benefit of his transaction being added to the blockchain. The fees also ensure the security of transaction on the network as miners cannot ignore the transactions or other miners will process it because it has a reward attached.

For the full node Bitcoin Core however, conditions for adding transactions to the blockchain are more specific, one of which is that transactions can only be added to a block with a block height that is one higher than the last.

Testnet3 Reset

A Testnet is an alternative Bitcoin Blockchain that is mostly used by developers to test their code, test edge case transactions and other development related subjects, the testnet is currently 1412193 blocks long and takes about 2 days to fully sync.

This caused some conversation on the bitcoin-dev mailing list calling for a reset of the testnet to make it sync faster and use less disk data, while some developers called for this, others actually called for a larger blockchain compared to the mainnet to find size-related errors. Developers like Jimmy Song and Johnson lau called for the existence of two testnets, one small and one large.

A Quick Overview of Bitcoin Testnet Block Generation
One of the strangest peculiarities in the Bitcoin Testnet is the way it generates blocks, to make testing easier on the testnet there’s a special rule in the consensus that if a block isn’t mined in the last 20 minutes the next block is going to reset the difficulty to 1, for reference the current Bitcoin Mainnet difficulty is 5363678461481.