CompTIA Security+ Question B-95

A security analyst discovered data such as images and word documents hidden within different types of files. Which of the following cryptographic concepts describes what was discovered?

A. Symmetric encryption
B. Non-repudiation
C. Steganography
D. Hashing

Answer: C

Explanation:
Steganography is the process of concealing a file, message, image, or video within another file, message, image, or video. Note: The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Plainly visible encrypted messages, no matter how unbreakable will arouse interest, and may in themselves be incriminating in countries where encryption is illegal. Thus, whereas cryptography is the practice of protecting the contents of a message alone, steganography is concerned with concealing the fact that a secret message is being sent, as well as concealing the contents of the message.

CompTIA Security+ Question A-19

Which of the following is true about asymmetric encryption?

A. A message encrypted with the private key can be decrypted by the same key
B. A message encrypted with the public key can be decrypted with a shared key.
C. A message encrypted with a shared key, can be decrypted by the same key.
D. A message encrypted with the public key can be decrypted with the private key.

Answer: D

Explanation:
Asymmetric algorithms use two keys to encrypt and decrypt data. These asymmetric keys are referred to as the public key and the private key. The sender uses the public key to encrypt a message, and the receiver uses the private key to decrypt the message; what one key does, the other one undoes.