What is the purpose of digital signatures?

• A. To increase file size
• B. To verify authenticity and integrity
• C. To compress data
• D. To accelerate data transmission

Answer: (B)

Digital signatures play a crucial role in ensuring the authenticity and integrity of a message or document. They are cryptographic tools that use mathematical algorithms to generate a unique code based on the content of the digital document and the sender's private key. When a sender creates a digital signature, it provides a way for the recipient to confirm that the message or document was indeed created by the claimed sender (authenticity) and that the content has not been altered during transmission (integrity).

When the recipient receives the document, they can verify the digital signature using the sender's public key. If the signature is valid, it ensures that the content is unchanged and originated from the legitimate sender. This process builds trust in digital communications, making digital signatures essential for secure transactions, legal documents, and various online communications.

In contrast, the other options do not accurately describe the purpose of digital signatures. For instance, increasing file size, compressing data, and accelerating data transmission do not pertain to the verification of authenticity or integrity, which are the fundamental aspects of digital signatures.