Classic Cloud Token Framework {#tms-ctf-intro}
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The Cloud Token Framework (CTF) is the framework for binding a device and a network token. CTF enables merchants to perform one-time issuer identification and verification and securely binds a user's device to a Visa network token. CTF reduces fraud rates and improves transaction conversion.

> IMPORTANT CTF is supported only in mobile in-app experiences.

Prerequisites
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In order to send device binding requests, you must have a self-signed certificate associated with your merchant account. See [Cloud Token Framework Key Generation](/docs/vas/en-us/tms/developer/all/rest/tms/tms-ctf-intro/tms-ctf-key-gen.md "").  
A token requestor must pass local authentication information. The token requestor can select up to two of these authentication factors for the cardholder to verify their identity at checkout:

Knowledge
:
Knowledge verification factors include information that only the cardholder knows. For example, a password.

Possession
:
Possession verification factors include something that only the cardholder has. For example, a pre-registered mobile phone, a card reader, or a key generation device.

Inherence
:
Inherence verification factors include something that the cardholder is. For example, biometric data. Biometric data includes facial recognition, a fingerprint, voice recognition, or a behavioral biometric.
IMPORTANT In markets where two-factor authentication is a regulatory requirement, token requestors must send both authentication factors and the two selected factors should be mutually independent. In all other markets, token requestors will have to perform single-factor authentication as a minimum requirement.