What is a digital signature?

A digital signature is fundamentally a hash of data that is encrypted using a private key. This process provides both data integrity and authenticity. When a sender creates a digital signature, they first generate a hash of the message using a cryptographic hash function. This hash, which is a fixed-size string representation of the data, is then encrypted with the sender's private key.

The key components of a digital signature include:

1. Authenticity: The digital signature verifies the identity of the sender. Only the sender who possesses the corresponding private key could have created that specific signature.

2. Data Integrity: The signature ensures that the message has not been altered in transit. If even a single character of the message changes, the hash will be different, and the signature will not validate.

3. Non-repudiation: Once a sender has signed a message, they cannot deny having sent it, as only they possess the private key associated with that signature.

The other options do not accurately represent the nature of a digital signature. While encrypting a message and file encryption are related to securing messages and files, they do not focus on the concept of a signature that validates both the source and the integrity of the data. Similarly, the