Bitcoin Basics and Cryptography Flashcards

What hashing algorithm does Bitcoin use for its proof-of-work mining process?

Answer: SHA-256

Bitcoin uses SHA-256 (Secure Hash Algorithm 256-bit) as the basis for its proof-of-work mining algorithm.

Which elliptic curve does Bitcoin use for its public-key cryptography?

Answer: secp256k1

Bitcoin uses the secp256k1 elliptic curve, which was chosen for its efficiency and security properties.

What is the purpose of a Bitcoin address compared to a public key?

Answer: A Bitcoin address is a hashed, encoded form of the public key for shorter, safer sharing

A Bitcoin address is produced by applying SHA-256 and RIPEMD-160 to the public key, then Base58Check encoding, providing a shorter and more error-resistant identifier.

What does 'immutability' mean in the context of the Bitcoin blockchain?

Answer: Once data is confirmed in the blockchain, it is computationally infeasible to alter it without redoing all subsequent proof-of-work

Bitcoin's immutability comes from chained cryptographic hashes and cumulative proof-of-work, making retroactive changes computationally prohibitive.

In Bitcoin's Script language, what does OP_CHECKSIG verify?

Answer: That a given signature is valid for the provided public key and transaction hash

OP_CHECKSIG pops a public key and signature from the stack and verifies the ECDSA signature against the transaction hash.

What is a 'coinbase transaction' in Bitcoin?

Answer: The first transaction in each block that creates new bitcoin and collects fees for the miner

The coinbase transaction is the mandatory first transaction in every Bitcoin block, through which miners receive the block subsidy plus transaction fees.

What is the maximum size of a standard Bitcoin block (pre-SegWit weight limit)?

Answer: 1 MB

Bitcoin's original block size limit was 1 MB, introduced by Satoshi to prevent spam; SegWit later introduced a 4 MB block weight limit.