> ## Documentation Index
> Fetch the complete documentation index at: https://docs.actioncodes.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Security & Determinism

> How Action Codes achieve security without on-chain state

<Note>
  This is advanced documentation about the protocol's security model. For integration guides, see the [Quick Start](/quickstart).
</Note>

The Action Codes Protocol is designed to offer cryptographic security and strict determinism without requiring persistent on-chain state or user sessions. Every code can be verified, traced, and resolved based entirely on public inputs and signatures.

#### Deterministic Code Generation

<Info>
  **Each Action Code is deterministically derived using the combination of:**

  * Public key (pubkey)
  * Time window (timestamp, rounded to 2-minute slots)
  * Namespace prefix (prefix)
  * Signature over a canonical message
</Info>

This ensures that:

* The same inputs will always produce the same code
* Multiple clients (relayers, wallets) can reproduce and validate the code without external coordination
* No central authority or database is required to issue or verify codes

#### Signature Binding

All codes are signed by the user’s wallet, ensuring:

* The user explicitly authorizes the creation of the code
* The code cannot be spoofed by any third party
* Verification only requires the signature and public key

Each signature is over a canonical string:

```text theme={null}
{prefix}:{code}:{timestamp}
```

This binding ensures replay protection and uniqueness within the time window.

#### Encrypted Payloads

Action Code objects are encrypted using the code itself as the symmetric key. This means:

* The code is the secret needed to decrypt and access transaction details
* Even if a relayer or database is compromised, attackers cannot view transaction intent or metadata without knowing the code
* This pattern supports stateless privacy and decentralization

Only the user who created the code (or anyone they share it with) can decrypt and act on it.

#### No On-Chain State or Sessions

* No wallet connection is needed to generate or resolve a code
* No smart contract is involved in the validation of the code itself
* All logic is executed locally or server-side via open protocol rules
* Transactions are finalized only after on-chain user signatures

#### Built-in Expiry & Grace Period

Codes include expiration timestamps and are valid only within a short window (e.g. 2–3 minutes):

* Prevents reuse or replay
* Encourages real-time interaction
* Relayers automatically reject expired codes

The protocol also allows ±1 slot tolerance for clock drift.