Glossary
17 terms · MIT BLC Module 2
Quick definitions of supporting terms. Major terms have their own concept pages, linked below.
0–9
- 51% attack
- Majority-control attack: one party controlling most of a network’s power can monopolize block production and reverse transactions. See 51% Attack →
B
- Block header
- Compact block summary anchored by a Merkle root. See Merkle Trees →
C
- Chaumian e-cash
- David Chaum’s 1980s private digital cash; still required a bank.
D
- Distributed lottery
- Gorbunov’s framing of mining; cryptographic sortition is the stake-weighted analog. See Pure Proof of Stake →
F
- Finality
- Guarantee that a block stays in the chain forever. See Pure Proof of Stake →
- Fork
- Two valid blocks extending the same parent; dead branches are abandoned (risking lost payments). See Proof of Work →
G
- Genesis block
- The first block in a chain; defined for free at system launch.
H
- Hash value
- Fixed-length output of a hash function; a data fingerprint. See Hash Functions →
L
- Longest-chain rule
- Build on the longest chain you see; how Proof of Work resolves forks. See Proof of Work →
M
- Miner
- Node doing Proof of Work to append blocks for a reward. See Mining and Mining Economics →
N
- nLocktime
- Rule making a transaction valid only after a set time. See UTXO Model →
- Nonce
- A number added to block data before hashing; varied repeatedly to find a valid hash. See Proof of Work →
P
- Permissionless
- Anyone can join without approval (a core Bitcoin property).
- Public / private key
- Shareable identifier / secret signer. See Public-Key Cryptography →
S
- scriptSig / scriptPubkey
- Bitcoin Script input signature / output spending predicate. See UTXO Model →
- Staking
- Locking tokens as collateral to participate in Proof of Stake. See Proof of Stake →
V
- Validator
- Staker who proposes and verifies blocks in Proof of Stake. See Proof of Stake →