What is a digital signature primarily used for?

A digital signature is primarily used to verify the authenticity and integrity of a message. It acts like a virtual fingerprint that ensures that the content of a message has not been altered during transmission and confirms the identity of the sender. This process typically involves the use of cryptographic algorithms to create a unique hash of the message, which is then encrypted using the sender’s private key. When the recipient receives the message, they can decrypt it with the sender's public key and compare the hash to ensure that the message has remained unchanged, thereby confirming both its authenticity and integrity.

While encryption is a core component of securing communications, a digital signature's primary role is not to encrypt messages for confidentiality; that purpose is typically fulfilled by other encryption methods. Additionally, digital signatures do not enhance the speed of data transmission or mask the sender’s identity; their main function centers on ensuring that the sender of a message is indeed who they claim to be and that the contents of the message have not been tampered with.