GSEC: GIAC Security EssentialsDemo

Question

Which two actions can the recipient of a PGP email message perform to enable trust to be established between the sender and receiver?

A Decode the message by decrypting the asymmetric key with his private key, then using the asymmetric key to decrypt the message.
B Decode the message by decrypting the symmetric key with his private key, then using the symmetric key to decrypt the message.
C Decode the message by decrypting the symmetric key with his public key, then using the symmetric key to decrypt the message.
D Decrypt the message by encrypting the digital signature with his private key, then using the digital signature to decrypt the message.

Explanation

PGP hybrid encryption encrypts the message with a symmetric session key and protects that session key with the recipient’s public-key encryption key. The recipient decrypts the symmetric session key using their private key, then uses the recovered symmetric key to decrypt the message. Sender authentication additionally depends on verification of a valid digital signature with the sender’s public key.

Learn more

Hybrid ciphers — The GNU Privacy Handbook

GSEC: GIAC Security EssentialsDemo

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Notes

Readiness

QuestionQ14

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