Which of the following BEST describes the process of creating a digital envelope?

Question

Options

• AThe encryption key is compressed within a folder after a message is encoded using symmetric
• BA message is encoded using symmetric encryption, and then the encryption key is secured using
• CThe message is hashed, and the hash total is sent using symmetric encryption.
• DA message digest is encrypted using asymmetric encryption, and the encryption key is sent using

• A
  5% (2)
• B
  90% (38)
• C
  2% (1)
• D
  2% (1)

Explanation

Option B is correct because a digital envelope is a two-step hybrid encryption process: the bulk message is encrypted with a fast symmetric key, and then that symmetric key itself is encrypted with the recipient's asymmetric (public) key. The recipient uses their private key to unwrap the symmetric key, then decrypts the message - combining the speed of symmetric encryption with the secure key exchange of asymmetric encryption.

Why the distractors are wrong:

• A is wrong because "compressing a key in a folder" is nonsensical as a security mechanism - it confuses file archiving with cryptographic key protection.
• C describes a message authentication code (MAC) or integrity check, not a digital envelope - hashing verifies integrity but doesn't provide confidentiality.
• D describes a digital signature (encrypting a message digest/hash with a private key), which proves authenticity, not a digital envelope, which provides confidentiality.

Memory tip: Think of it literally - you put a letter (message, locked with a fast symmetric key) inside an envelope, then seal the envelope with the recipient's public key (asymmetric). Only the recipient can open the outer envelope to retrieve the inner key.

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