A USB security token is a small hardware device that helps prove your identity to a computer or online service.
It can be used for:
- Two-factor authentication (2FA): You insert the token and press or activate it when signing in.
- Passwordless login: The token can authenticate you without a conventional password.
- Cryptographic signing: It can sign documents, software, or authentication challenges.
- Secure key storage: Private cryptographic keys remain inside the token rather than being stored on the computer.
- Access control: It can unlock protected computers, applications, networks, or encrypted data.
In this project, the STM32 microcontroller communicates with the computer over USB and runs the token’s firmware. Ideally, it generates or stores a private key and performs cryptographic operations internally. The computer receives only the signed response—not the private key itself.
The hardware alone does not automatically provide security. It also needs appropriate firmware and protocols, such as FIDO2/WebAuthn, U2F, HOTP/TOTP, or OpenPGP. Furthermore, a standard STM32F103 is not a dedicated secure element, so additional protection may be needed for strong resistance against physical attacks.