# Layer 2: Access Control & Native AA (The Gatekeeper)

Layer 2 acts as the intelligent "Gatekeeper" of the Blockchain. Here, Bullbit executes a digital identity revolution by replacing default authentication logic with a **Custom AnteHandler** deeply integrated into the protocol.

* **Native Multi-Curve Support:** BullChain breaks compatibility barriers by simultaneously supporting two cryptographic signature standards at the Native layer:
  * **secp256k1:** For traditional Crypto wallets and automated trading bots.
  * **secp256r1 (NIST P-256):** For WebAuthn/Passkey standards. This means BullChain Validators can "understand" and directly verify signatures generated from the Secure Enclave on iPhone/Android without going through any intermediate Smart Contracts, turning personal devices into Hardware Wallets with the highest security level.
* **Stateful Verification for High Frequency:** BullChain's AnteHandler accesses the **SessionStore** directly to verify transactions. This process eliminates cumbersome sequential **Nonce** checks (a bottleneck of Ethereum), allowing **Liquidity Providers (LPs)** and professional Traders to send batches of parallel orders without worrying about stuck transactions due to Nonce errors.
* **Protocol-Level Gas Abstraction:** Fee Grant logic is no longer an external application but is **Hard-coded** into the Blockchain logic. The system automatically identifies valid transactions from user Passkeys and executes a Gas waiver mechanism right at the gateway. For end-users, the concept of "Gas" is completely invisible.