Glossary

100+ terms covering the Covenant language, cryptographic primitives, and ecosystem concepts.

A

action — The primary entry point declaration in a Covenant contract. Maps to an ABI-visible function. May be annotated with @view, @nonreentrant, @pq_signed, etc.

ABI — Application Binary Interface. The JSON descriptor of a contract’s public actions, events, and errors. Covenant emits a fully typed ABI compatible with ethers.js and viem.

amnesia { } — A block-scoped keyword that triggers the two-pass cryptographic erasure protocol. State mutations inside the block are provably erased at the end of the block.

assert — Unconditional invariant check. Reverts with Panic(0x01) if the condition is false.

Aster Chain — EVM-compatible L1 (Chain ID 1996) launched March 5, 2026. Features native FHE precompiles, ZK proof verification, and PoSA consensus.

@allow(..) — Compiler annotation that suppresses a specific lint detector.

B

@before — Guard decorator that causes the guard to run before every action in the contract.

Beacon Proxy — EIP-1967 upgrade pattern where many proxies share a single beacon. See chapter 13.

BGV — Brakerski-Gentry-Vaikuntanathan. An FHE scheme optimised for integer arithmetic.

block.number — Built-in: the current block number.

block.timestamp — Built-in: UNIX timestamp of the current block (seconds). Can be manipulated by validators ±15 seconds.

Bool — Primitive boolean type. Compiles to uint8 in the ABI.

Bytes — Dynamic byte array. Compiles to bytes in the ABI.

Bytes32 — Fixed 32-byte value. Compiles to bytes32 in the ABI.

C

CEI — Checks-Effects-Interactions. The canonical safe action body ordering.

call() — Low-level external call primitive. Returns (success: Bool, data: Bytes).

Circuit — A ZK arithmetic constraint system. Identified by string IDs registered at contract init time.

CKKS — Cheon-Kim-Kim-Song. An FHE scheme for approximate real-number arithmetic.

contract — Top-level declaration for a Covenant smart contract.

covenant.toml — The project configuration file.

Covenant CLI — The command-line toolchain (covenant-cli).

CRYSTALS-Dilithium — Lattice-based digital signature algorithm standardised as NIST FIPS 204.

D

decimals — ERC-20 field indicating decimal places (typically 18).

delete — Resets a storage slot to zero. Inside amnesia { }, triggers two-pass erasure.

Dilithium3 — CRYSTALS-Dilithium parameter set (NIST level 2). PK: 1952 B, Sig: 3293 B.

Dilithium5 — Higher security parameter set (NIST level 5).

E

EIP-1967 — Standard storage slot layout for proxy contracts.

EIP-1822 — Universal Upgradeable Proxy Standard. Defines the proxiableUUID() check.

EIP-712 — Typed structured data signing standard.

emit — Emits an event. Must not reference amnesia-deleted fields.

encrypted<T> — The FHE ciphertext type. T may be u8–u256 or Bool.

error — Named revert reason declaration. Use revert ErrorName(...) or require(cond, Err).

ERC-20 — Ethereum fungible token standard. See chapter 06.

event — Structured log entry declaration. Up to 3 indexed fields per event.

EVM — Ethereum Virtual Machine. Covenant’s primary compilation target.

F

fhe_add(a, b) — Homomorphic addition of two encrypted<T> values.

fhe_decrypt(c, key) — Decrypts an encrypted<T> ciphertext, emitting an on-chain proof.

fhe_encrypt(v, pubkey) — Encrypts a plaintext value under a public key.

fhe_eq(a, b) — Homomorphic equality comparison. Returns encrypted<Bool>.

fhe_lt(a, b) — Homomorphic less-than comparison. Returns encrypted<Bool>.

fhe_mul(a, b) — Homomorphic multiplication.

fhe_owner_key() — Built-in: the deployer’s FHE public key.

fhe_reencrypt(c, pubkey) — Re-encrypts under a different public key without decrypting.

fhe_sub(a, b) — Homomorphic subtraction.

fhe_zero() — Returns an encryption of zero; initialises encrypted<T> fields.

FHE — Fully Homomorphic Encryption. Supports arbitrary computation on ciphertext.

field — Persistent storage declaration. Compiles to EVM storage slots.

fflonk — PLONK variant with smaller proof sizes. Supported by Covenant ZK backend.

G

guard — Named boolean predicate for access control.

Groth16 — Most widely deployed ZK proof system. ~200 B proof, ~280K gas verify.

H

Halo2 — ZK proof system with no trusted setup. ~1.2 KB proofs.

I

i256 — Signed 256-bit integer. Compiles to int256 in the ABI.

indexed — Event field modifier for Bloom filter topics (max 3 per event).

init — Constructor block. Runs once at deployment.

interface — External contract ABI declaration for typed external calls.

internal — Action modifier: not exposed in ABI, callable only from within the contract.

K

keccak256 — Built-in hash function. Takes Bytes, returns Bytes32.

L

Lattice cryptography — Mathematical foundation for post-quantum schemes. Quantum-resistant.

List<T> — Dynamic array. Length in base slot; elements at keccak256(base) + i.

LSP — Language Server Protocol. Covenant ships an LSP with 38+ lint detectors for VS Code.

M

Map<K, V> — Hash-map type. Compiles to keccak256(key . slot) storage layout.

msg.sender — Built-in: the caller’s address.

msg.value — Built-in: ETH (wei) sent with the call.

N

NIST FIPS 204 — Federal standard (August 2024) standardising CRYSTALS-Dilithium.

@nonreentrant — Prevents reentrant calls via a reentrancy lock storage slot.

Nonce — Monotonically increasing counter preventing replay attacks.

O

only() — Guard invocation. only(owner), only(role: R), or only(expr).

oracle_price — Built-in on Aster Chain: stake-weighted median price from validator committee.

OMEGA V4 — Security audit by OMEGA Security Labs on Covenant v0.7.0-rc3. 41 findings, all resolved.

P

@pq_hybrid — Accepts both ECDSA and Dilithium3 signatures.

@pq_signed — Replaces ECDSA with Dilithium3 (NIST FIPS 204).

Pagefind — Static search library used by this documentation site.

PLONK — Universal ZK proof system with a universal trusted setup.

PoSA — Proof-of-Staked Authority. Aster Chain’s consensus mechanism.

Post-quantum — Cryptographic schemes secure against quantum computers.

prevrandao — EVM opcode providing validator-contributed randomness (post-Merge).

proxiableUUID() — ERC-1822 magic value identifying a UUPS implementation.

R

register_circuit — Built-in for registering a ZK verification key at contract init time.

require(cond, Err) — Reverts with Err if cond is false.

revert Err(..args) — Unconditional typed revert.

Role — Named access-control group declared with role. Managed by grant_role/revoke_role.

S

STARK — Scalable Transparent ARguments of Knowledge. No trusted setup; post-quantum secure.

String — Dynamic UTF-8 string. Compiles to string in the ABI.

staticcall — Read-only external call emitted for @view action cross-contract calls.

T

TFHE — Fast Fully Homomorphic Encryption over the Torus. Covenant default FHE scheme.

Timelock — Enforces a waiting period before governance actions execute.

transfer_eth(to, amount) — Built-in ETH transfer without 2300-gas stipend restriction.

U

u8 / u16 / u32 / u64 / u128 / u256 — Unsigned integer types. Overflow reverts by default.

unchecked { } — Block disabling overflow checking. Use only when overflow is provably impossible.

UUPS — Universal Upgradeable Proxy Standard (EIP-1822 / EIP-1967). See chapter 12.

V

verify_pq_sig — Built-in: verifies a Dilithium3 signature. Injected by @pq_signed.

@view — Marks an action as read-only. Compiler enforces no state mutations.

Viewer Pass — Aster Chain selective disclosure mechanism: grants read access to encrypted state without exposing data to other validators.

W

WASM — WebAssembly. A Covenant compilation target for off-chain proving and testing.

Z

zk_prove(circuit, private_inputs, public_inputs) — On-chain ZK proving (practical for < 2^16 constraints).

zk_verify(circuit, proof, pub_inputs) — Verifies a ZK proof on-chain. Returns Bool.

ZkProof — Covenant’s native ZK proof blob type with circuit-binding commitment header.

Zero-knowledge proof — Allows proving a statement is true without revealing the witness. See chapter 10.