Wallet Verification
Wallet verification gates blockchain write operations as a second security layer beyond session authentication, using PIN, TOTP, or backup-code checks.
Overview
Wallet verification is the per-request check that protects blockchain write operations from browser sessions. Even with a valid authenticated session, a signing request must include PIN, TOTP, or backup-code evidence before DALP passes the operation to the signing flow.
Related
System context
Why wallet verification exists
Session authentication proves identity. Wallet verification proves intent for the request that will consume a wallet secret. Separating these checks means a browser session alone cannot trigger asset transfers, minting, burning, or other signing operations protected by the wallet-verification middleware.
The check runs before signing. DALP rejects the request before the signing flow starts when verification evidence is missing, the selected method is not configured for the user, or the credential is wrong.
See the security overview for how this check combines with authentication, authorization, custody policy, and on-chain transfer controls.
Verification methods
Transaction-signing APIs accept these wallet verification methods. Organizations can enable one or more based on their security posture.
PINCODE
A 6-digit PIN set during initial wallet setup. PIN verification provides quick confirmation for routine transactions where the user is already authenticated and working within the platform.
- Setup: User defines PIN during wallet creation
- Usage: Enter 6-digit code alongside the transaction request
- Trade-off: Fastest verification, lower resistance to shoulder-surfing compared to TOTP
Two-factor authentication (TOTP)
Time-based one-time passwords generated by an authenticator app. Codes rotate every 30 seconds following RFC 6238.
- Setup: User scans a QR code into their authenticator app during wallet setup
- Usage: Enter the current 6-digit code from the authenticator app
- Trade-off: Stronger than PIN (codes expire), requires the user's authenticator device
Backup codes
Backup codes are one-time recovery codes generated during wallet setup. DALP generates 16 codes in xxxxx-xxxxx format. Each code can pass verification once; reuse fails because DALP records used codes.
- Setup: Platform generates and stores the active code set during wallet configuration; user stores the codes securely offline
- Usage: Enter any unused code when PIN or TOTP is unavailable
- Trade-off: Last-resort recovery mechanism; limited supply, one use per code
Passkeys and wallet verification
Passkeys can be used for account authentication when enabled for the deployment. DALP documents passkey sign-in on the Authentication page.
For blockchain write requests, the wallet verification middleware accepts PINCODE, OTP, or SECRET_CODES. Passkeys are not a wallet verification type — they authenticate account sign-in only.
How verification works in requests
API procedures that trigger blockchain write operations accept a walletVerification object in the request body:
| Field | Value | Description |
|---|---|---|
walletVerification.verificationType | PINCODE, OTP, or SECRET_CODES | Which wallet verification method the user presents |
walletVerification.secretVerificationCode | 6-digit string, TOTP code, or backup code | The credential for the selected verification method |
The Platform API validates the credential before forwarding the operation to the Workflow Engine. If verification fails, the request is rejected immediately. No gas is consumed, no custody provider interaction occurs, and no on-chain state changes.
API key sessions bypass verification
When a request is authenticated via API key, wallet verification is not required. The walletVerification field can be omitted from the request body. API keys are scoped credentials intended for machine-to-machine use. The API key is the authorization factor, so a second interactive challenge is not part of that path.
Failure cases
Wallet verification fails before the signing flow starts. The request is rejected when:
| Condition | Result |
|---|---|
| No authenticated user is available | UNAUTHORIZED with Authentication required |
| The user has no PIN, backup-code, or TOTP method configured | USER_MISSING_2FA with setup guidance |
The request omits walletVerification for a browser-session write | BAD_REQUEST with Wallet verification is required |
| The selected method is not configured for the user | FORBIDDEN |
| The submitted PIN, backup code, or TOTP code is invalid or already used | FORBIDDEN |
| Too many failed PIN, backup-code, or TOTP attempts in a short window | FORBIDDEN with a retry message and seconds to wait |
When repeated verification attempts fail, DALP temporarily locks the affected verification method for that user. Further attempts are rejected with a FORBIDDEN response whose message states how many seconds to wait before retrying. While the lockout is active, the request is rejected before the credential is checked, so even a correct value must wait for the window to expire. A successful verification before the threshold is reached clears the recorded failures. The lockout covers the PIN, backup-code, and TOTP paths; remote identity-provider verification is handled by that provider.
Passkeys authenticate account sign-in. PINCODE, OTP, and SECRET_CODES are the accepted wallet verification values for transaction-signing requests.
Security considerations
- Separate credential path: Wallet verification uses wallet-specific PIN, backup-code, or TOTP records rather than the browser session token.
- Method-level configuration: A user must have the selected method enabled before that method can satisfy a signing request.
- Replay prevention: Backup codes are recorded on use, and TOTP tokens are tracked so the same token cannot be replayed.
- Brute-force protection: Repeated failed PIN, backup-code, or TOTP attempts temporarily lock the affected method for that user and fail closed, blunting online guessing of a low-entropy secret from a compromised session. A successful verification resets the count.
- API-key exception: Machine-to-machine API-key sessions skip the interactive wallet-verification challenge.
See also
- Security overview for the full defense-in-depth model
- Signing Flow for how wallet verification fits into the transaction lifecycle
- Authentication for API-level rate limiting and RBAC
Vendor governance
DALP separates platform controls from the third-party services, operating procedures, and regulatory evidence that a financial institution owns when it assesses outsourcing, DORA, and vendor governance obligations.
Bridge and cross-chain
Understand where DALP controls end in bridge, wrapper, redemption, and XvP designs, and which external-route evidence an operator must own before production.