Glossary

A

Admin Signature: A cryptographic signature generated by an authorized party (e.g., the Veilnet sequencer) to approve certain on-chain actions, like withdrawals.

Anonymity Set: The set of users that could plausibly be the sender or receiver of a transaction. Larger anonymity sets provide better privacy.

B

Base: An EVM-compatible blockchain that Veilnet supports for privacy-preserving transactions.

Bridge: A cross-chain mechanism for moving assets from one blockchain to another.

Burn: The permanent removal of tokens from circulation, typically achieved by sending them to an unspendable address.

C

Commitment: A cryptographic hash or encrypted structure representing a user's private balance or state.

Contract-Level Privacy: Privacy logic enforced directly within a smart contract rather than at the application or database level.

D

Deposit: The action of moving funds from a public wallet into the Veilnet vault.

Deterministic State Accumulator: A cryptographic structure (like a Merkle tree) that represents all user balances and can be verified on-chain without storing individual balances.

E

Encrypted Payload: A secure, encrypted message containing sensitive transaction details (e.g., recipient address, amount).

EVM: Ethereum Virtual Machine, the execution environment for smart contracts on Ethereum-compatible blockchains.

F

Front-Running: A malicious attack where an observer places their transaction ahead of a target transaction to manipulate outcomes (e.g., extracting MEV).

G

Gas: A unit of computational cost on the blockchain, paid to miners/validators.

H

Hash: A deterministic output from a cryptographic function. Changing any input produces a completely different hash.

K

Keccak-256: A cryptographic hash function used by Ethereum and compatible chains.

L

Leaf: A single node in a Merkle tree, typically representing a user's balance or commitment.

M

MEV (Maximal Extractable Value): The profit that can be extracted by reordering, including, or excluding transactions.

Merkle Proof: A cryptographic proof demonstrating that a specific leaf exists within a Merkle tree without revealing the entire tree.

Merkle Root: The top hash of a Merkle tree, representing the state of all leaves below it.

Merkle Tree: A cryptographic data structure where each node is a hash of its children, enabling efficient verification of large datasets.

Mixer: A privacy tool that accepts deposits in fixed amounts and releases them through withdrawal addresses, breaking the link between depositor and withdrawer.

N

Nullifier: A unique hash generated when a commitment is spent, marked on-chain to prevent replay attacks.

P

Privacy: The property of keeping sensitive information (balances, addresses, transaction amounts) hidden from public observation.

Proof: A cryptographic attestation that something is true (e.g., "I own this balance") without revealing the underlying data.

R

Relay Network: Nodes that submit transactions on behalf of users, often used to obscure sender identity for gas-less transactions.

Root: The top node of a Merkle tree, serving as a compact representation of the entire tree's state.

S

Sequencer: A centralized or semi-decentralized entity responsible for ordering and executing state transitions in a secure environment.

Shielded: Hidden or encrypted, such as shielded balances or shielded transfers that are not visible on-chain.

Shielded Address: A recipient address within Veilnet that can receive private transfers without being publicly linked to the transfer.

Signature: A cryptographic proof of authorization, typically signed with a private key and verified with a public key (EIP-712 for typed data).

Stateless Execution: Computation that occurs off-chain or in a separate layer, with results verified on-chain without storing intermediate state.

T

Transaction: An atomic unit of work on the blockchain, changing state and often incurring gas costs.

Timestamp: The on-chain block time at which a transaction was included, potentially revealing timing information.

U

Unshield: To move funds from a shielded balance back to a public wallet address.

V

Vault: The smart contract that holds pooled user funds and verifies state transitions via Merkle proofs.

W

Wallet: A software or hardware tool for managing private keys and signing transactions.

Withdraw: To claim funds from the Veilnet vault back to a public blockchain address.

Z

Zero-Knowledge (ZK) Proof: A cryptographic proof that a statement is true without revealing any information beyond the truth of the statement itself.

ZK Circuit: A mathematical representation of a computation that can be converted into a zero-knowledge proof.