BLEPM flashcards
BLEPM · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Append-only ledger
- A data structure where confirmed records can only be added, never altered or deleted in place; corrections are new entries, preserving a verifiable history for audit.
- Merkle proof
- A logarithmic-size path of sibling hashes proving a transaction belongs to a block without revealing the whole block; verification recomputes hashes up to the stored root.
- UTXO model
- Funds exist as unspent transaction outputs consumed whole by inputs, with change returned to a new output; balances are derived by summing outputs.
- Probabilistic finality
- A transaction becomes increasingly irreversible as later blocks build on it; confidence grows with depth, and deep reorgs remain theoretically possible.
- Deterministic finality
- A consensus protocol commits a block irrevocably once a defined quorum confirms it; no later fork can revert the transaction without protocol violation.
- Fabric channel
- A private subnet of a Hyperledger Fabric network with its own ledger and membership; transactions on one channel are invisible to peers not joined to it.
- Endorsement policy
- A rule specifying which organizations or peers must simulate and sign a transaction proposal before it is ordered; it enforces multi-party approval on state changes.
- Ordering service
- The Fabric component that receives endorsed transactions, establishes their total order, batches them into blocks, and delivers blocks to committing peers.
- Membership service provider
- A Fabric component that maps X.509 certificates to organizational identities and roles, defining who may join the network and act within it.
- Corda notary
- A service that confirms a transaction's inputs are unique and unconsumed, preventing double spends without broadcasting every transaction to all participants.
- Private data collection
- A Fabric feature storing specified state keys only on authorized peers, with a hash on the channel ledger so others can verify but not read the data.
- Proof-of-work
- A Sybil-resistance mechanism requiring miners to find a nonce producing a block hash below a target, making history rewriting economically and computationally expensive.
- Slashing
- A proof-of-stake penalty destroying part of a validator's locked stake when provable misbehavior such as double signing or conflicting attestations occurs.
- Byzantine fault tolerance
- Consensus that tolerates faulty or malicious nodes; classic BFT protocols require n = 3f + 1 replicas to tolerate f faulty participants.
- Reentrancy attack
- An exploit where a contract calls an untrusted contract that calls back before state is updated, allowing repeated withdrawals; prevented by updating state first.
- Chaincode lifecycle
- The Fabric v2 process of packaging, installing, approving, and committing chaincode with a sequence number and endorsement policy agreed by channel members.
- Gas limit
- The maximum computation a transaction or block may consume on Ethereum; execution halts and reverts when gas is exhausted, bounding node workload.
- Consensus selection rule
- Choose PoW or PoS for open adversarial networks, crash-fault-tolerant protocols for trusted consortia, and BFT protocols when members may act maliciously.
- Blockchain fit test
- A use case qualifies when several organizations need a shared consistent record, no trusted intermediary exists, and reconciliation or dispute costs are material.
- Process re-engineering first
- Redesign the inter-organizational process before deploying a ledger; mirroring existing silos on-chain adds cost and latency without removing reconciliation.
- Anchor participant
- A large, motivated organization whose transaction volume and authority draw smaller counterparties onto a consortium network, creating the required network effect.
- Tokenized asset
- A digital representation of a real-world asset on a ledger; enforceability depends on legal recognition, custody arrangements, and settlement finality rules.
- Verifiable credential
- A tamper-evident digital claim issued by an authority and held by a subject, cryptographically verifiable without contacting the issuer at verification time.
- Crypto-shredding
- Deleting or rotating the encryption key so encrypted on-chain data becomes permanently unreadable, approximating erasure while preserving ledger immutability.
- Attribute-based access control
- Authorization decisions based on attributes embedded in a participant's certificate, such as role or organization, evaluated by chaincode or network policy.
- HSM for signing keys
- A tamper-resistant hardware module storing private keys and performing signatures internally, preventing key extraction and enforcing separation of duties.
- Idempotent submission
- Retrying a transaction with the same unique identifier so duplicate submissions cannot double-apply state; the client then queries the ledger to confirm outcome.
- Hash time-locked contract
- An atomic-swap mechanism releasing funds only when a secret preimage is revealed before a deadline; otherwise funds return to the sender.
- Outbox pattern
- A design writing state changes and outgoing events in one local transaction, then publishing asynchronously, avoiding lost or duplicated cross-system updates.
- Consortium agreement
- A signed multi-party contract defining membership admission, voting thresholds, upgrade approval, cost sharing, dispute resolution, data ownership, and exit terms.
- Settlement finality
- The legal and technical point at which a transfer is irrevocable and cannot be reversed; it must be established in the governing agreement and platform design.
- Proof of concept
- A limited build validating one process on a chosen platform with sample data; it tests technical feasibility before counterparties and production integration are committed.