Digital Signature: Ensuring Email Security

What key should Amanda use to sign the email she is sending to Maria?

A. Maria's public key

B. Amanda's public key

C. Maria's private key

D. Amanda's private key

Answer:

Amanda should use her private key to digitally sign an email. The digital signature is created by encrypting the message hash with her private key. Maria would use Amanda's public key to verify the signature's authenticity.

When Amanda wants to use a digital signature on an email she is sending to Maria, she should use her own private key. The process of signing an email with a digital signature involves creating a hash of the message and encrypting it with the sender's private key. This encrypted hash, in effect, becomes the digital signature. The recipient, in this case Maria, will use Amanda's public key to decrypt the message and verify the authenticity of the digital signature, ensuring the message's integrity and confirming Amanda's identity.

Using digital signatures is crucial for email security as it provides a way to ensure the authenticity, integrity, and non-repudiation of the message. By using encryption and decryption keys in this way, only the intended recipient can decrypt the message and verify that it was indeed sent by the claimed sender. This helps prevent tampering, impersonation, and ensures the privacy of communication.

Implementing digital signatures is a key aspect of secure communication in today's digital age. Understanding how to use private and public keys for encryption and decryption is essential for maintaining the confidentiality and reliability of electronic communications.