What does a digital signature do?

A digital signature serves the crucial purpose of verifying the authenticity and integrity of a digital message or document. When a sender applies a digital signature using their unique private key, it creates a unique hashed representation of the document that is virtually impossible to forge. This signature allows the recipient to confirm that the message indeed comes from the purported sender and that it has not been altered while in transit.

The process involves the use of cryptographic algorithms, ensuring that if the document is modified after the signature is applied, the signature will no longer match the altered content. This mechanism plays a vital role in securing communications and transactions in digital environments, particularly in areas requiring high levels of trust, such as financial services, legal agreements, and software distribution. Thus, the main function of a digital signature is to assure both the authenticity of the sender and the integrity of the data being transmitted.