Glossary

A

Admin

The public key that owns and controls a Settings account. Only the admin can update settings or transfer ownership.

Anchor

A framework for Solana smart contract development that simplifies account serialization, error handling, and testing.

C

Callback

An instruction in your program that Range calls after successful verification when using verify_range_with_callback. The callback receives cpi_data and remaining_accounts.

CPI (Cross-Program Invocation)

The mechanism by which one Solana program calls another. Range supports both being called via CPI and making CPI calls to other programs.

cpi_data

Arbitrary bytes passed from verify_range_with_callback to your callback instruction. You define the format and meaning.

E

Ed25519

The digital signature algorithm used by Solana and Range. Provides 128-bit security level for signature verification.

Event

Data emitted by a Solana program during execution. Range emits VerificationSuccess events on successful verification.

I

IDL (Interface Definition Language)

A JSON file describing a Solana program’s instructions, accounts, and types. Used by Codama to generate type-safe clients.

Instructions Sysvar

A special Solana account (SysvarInstructions111111111111111111111) that provides information about the current transaction’s instructions. Used for CPI verification.

M

Message

The data signed by the backend and verified on-chain. Default format: {timestamp}_{pubkey}. Can be extended with additional fields.

P

PDA (Program Derived Address)

An address deterministically derived from seeds and a program ID. Cannot have a corresponding private key. Range Settings accounts are PDAs derived from ["settings", admin_pubkey].

Pubkey

Short for “public key.” A 32-byte identifier for accounts and signers on Solana, typically displayed in Base58 encoding.

R

range_signer

The public key of the trusted backend signer stored in a Settings account. Only signatures from this key are accepted for verification.

remaining_accounts

Additional accounts passed to verify_range_with_callback that are forwarded to your callback instruction. Access them by index in your on_verify handler.

Replay Attack

An attack where a valid signature is reused after its intended use. Range mitigates this with timestamp validation within window_size.

S

Settings

The account type that stores Range configuration: bump, admin, window_size, and range_signer. Each admin has their own Settings PDA.

Signature

A 64-byte Ed25519 digital signature created by the backend and verified on-chain. Proves the message was signed by the range_signer.

Signer

The account that signs a transaction. In Range verification, the transaction signer must match the pubkey in the signed message.

T

Timestamp

Unix timestamp (seconds since epoch) included in the signed message. Must be within window_size of the current on-chain time.

V

VerificationSuccess

Event emitted when verify_range or verify_range_with_callback succeeds. Contains signer, timestamp, signature, message, clock_slot, clock_timestamp, and settings_admin.

verify_range

The core verification instruction. Verifies a backend-signed message without triggering a callback.

verify_range_with_callback

Verification instruction that calls your program after successful verification. Enables atomic verification + action patterns.

W

window_size

Configuration in Settings that determines how long (in seconds) a signature remains valid. Smaller values are more secure but less tolerant of latency.