Encryption

Question 1

AES (Advanced Encryption Standard)

Answer 1

Symmetric
Type: 128-bit block
Key: 128, 192 or 256 bits
Notes: Fast (only requires one pass), efficient, strong

Question 2

DES (Data Encryption Standard)

Answer 2

Symmetric
Type: 64-bit block
Key: 56 bits
Notes: Small key = vulnerable to brute-force attacks

Question 3

3DES (Triple DES)

Answer 3

Symmetric
Type: 64-bit block
Key: 56, 112, 168 bits
Notes: Encrypts in 3 passes of DES algorithm w/multiple keys

Question 4

RC4

Answer 4

Symmetric
Type: Stream
Key: 40-2048 bits
Notes: Not recommended b/c NSA believed able to break

Question 5

Blowfish

Answer 5

Symmetric
Type: 64-bit block
Key: 32-448 bits
Notes: Considered strong and can be faster than AES

Question 6

Twofish

Answer 6

Symmetric
Type: 128-bit block
Key: 128, 192, 256 bits
Notes:

Question 7

RSA

Answer 7

Asymmetric
Key size: recommended minimum of 2,048 bits
Notes: Uses static keys
Uses mathematical properties of prime numbers
Widely used

Question 8

ECC (Elliptic curve cryptography)

Answer 8

Asymmetric
Notes: Doesn’t take as much processing power as other crypto methods so often used on low-power devices.
It uses mathematical equations to formulate an elliptical curve then graphs points on the curve to create keys.

Question 9

DH (Diffie-Hellman)

Answer 9

Key exchange algorithm used to privately share a symmetric key between two parties. Once the two parties know the symmetric key, they use symmetric encryption to encrypt the data.
Uses both static and ephemeral keys.

Question 10

DHE (Diffie-Hellman Ephemeral

Answer 10

Uses ephemeral keys, generating different keys for each session.
Sometimes known as EDH

Question 11

ECDHE (Elliptic Curve Diffie-Hellman Ephemeral)

Elliptic Curve Diffie-Hellman (ECDH)

Answer 11

Uses ephemeral keys generated using ECC

Uses static keys generated using ECC

Question 12

S/MIME (Secure/Multipurpose Internet Mail Extensions)

Answer 12

One of the most popular standards used to digitally sign and encrypt email.
Uses RSA for asymmetric encryption and AES for symmetric encryption

Question 13

PGP/GPG (Pretty Good Privacy / GNU Privacy Guard)

Answer 13

Method used to secure email communication. It can encrypt, decrypt, and digitally sign email.
Each of the PGP versions uses the RSA algorithm and public and private keys for encryption and decryption.
Uses both asymmetric and symmetric encryption.