DSC token–based signing (Class 3 Digital Signature Certificate) is a secure and legally compliant method of digital signing, recognized under the Indian IT Act, 2000, and governed by Controller of Certifying Authorities (CCA) guidelines. This method uses a physical USB device, known as a DSC token, to digitally sign documents in a controlled and trusted manner.

The DSC token securely stores the signer’s digital identity and a private signing key, which functions as the digital equivalent of a handwritten signature. This private signing key is securely locked within the token hardware and cannot be copied, extracted, by the computer or any external application. As a result, the signing authority always remains under the direct control of the signer.

To sign a document, the user connects the DSC token to the system and authenticates using a PIN. The signing operation is performed entirely within the token itself, and only the signed output is returned to the system. At no point does the private signing key leave the token.

This hardware-based signing approach ensures high security, non-repudiation, and protection against misuse or fraud. Since the signing process requires physical possession of the token and PIN authentication, it prevents unauthorized use and ensures that documents are signed only by the intended signer. Due to these safeguards, DSC token–based signing is widely used for legally binding and high-value documents, making it one of the most reliable digital signing methods available.

Contract360 enables users to digitally sign contracts using DSC tokens, where the digital certificate is securely stored on a USB device. This method works on Windows systems and provides a safe and legally valid way to sign documents electronically.