Encryption Solutions

Question 1

Block Cipher

Answer 1

A block cipher is a method of encrypting data in fixed-size chunks (called blocks) using a secret key.
Each block of plaintext (for example, 128 bits) is transformed into a block of ciphertext of the same size.

It works like a codebook: the same input block with the same key always produces the same encrypted output. Examples include AES and DES.

Question 2

Stream Cipher

Answer 2

A stream cipher encrypts data one bit or byte at a time, using a continuously changing key stream.

It works like mixing your data with a random-looking stream of bits (often using XOR). This makes it fast and good for streaming data, such as video or voice. Examples include RC4 and ChaCha20.

Question 3

Symmetric Encryption (Pre-Shared Key, PSK)

Answer 3

The same key handles the encryption/ decryption

Question 4

Asymmetric Encryption

Answer 4

Use a key pair to perform encryption/ decryption, one key encrypts, another decrypts

Encrypt Key = Public Key

Decrypt Key = Private Key

Question 5

Key Exchange

Answer 5

Symmetric Encryption schemes use Asymmetric Encryption to safely share the key used for Symmetric Encryption.

Asymmetric Encryption can simply send the public key over as plain text, since it has no value to an attacker.

Question 6

Small Key Lengths

Answer 6

-Weaker
-Less CPU Intensive
-Faster

Question 7

Large Key Lengths

Answer 7

-Stronger
-More CPU Intensive
-Slower

Question 8

Hash Salting

Answer 8

Adding a random string to a value which is being hashed in order to randomize it further.

This protects against attackers using known hashes to break commonly used passwords.

Question 9

Key Stretching

Answer 9

Running a file through multiple hashing algorithms in a row to further protect the original file