Crypto

The contract runtime exposes a small deterministic crypto module focused on Ed25519 verification and key-shape validation.

Available Functions

crypto.verify(vk, msg, signature)
crypto.key_is_valid(key)

crypto.verify(...)

crypto.verify(vk, msg, signature) returns True when:

• vk is a valid 32-byte Ed25519 public key encoded as hex
• signature is a valid Ed25519 signature in hex
• the signature matches the UTF-8 encoded msg string

If the key and signature decode cleanly but the signature does not verify, it returns False. Malformed hex inputs or an invalid Ed25519 public-key shape can raise before signature verification runs, so validate untrusted public keys with crypto.key_is_valid(...) before calling crypto.verify(...).

Typical uses include:

• permit-style approvals
• signed off-chain authorizations
• relayed action authorization patterns

crypto.key_is_valid(...)

crypto.key_is_valid(key) is a lightweight shape check.

It returns True only when the provided string is:

• exactly 64 hex characters
• valid hexadecimal

This is a format check, not a proof that the key controls funds or belongs to a specific account role.

Design Guidance

• hash or serialize the exact message format before users sign it
• keep message construction deterministic
• use crypto.key_is_valid(...) for input validation, not for authorization
• remember that signature verification is public and deterministic; there is no private key handling inside the contract runtime