Cryptography

Question 1

SHA-1

Answer 1

Hash - Developed by the NSA (National Security Agency), SHA-1 produces a 160-bit value output, and was required by law for use in U.S. government applications.

Question 2

RSA

Answer 2

Asymmetric algorithm - An algorithm that achieves strong encryption through the use of two large prime numbers. Factoring these numbers creates key sizes up to 4,096 bits. RSA can be used for encryption and digital signatures and is the modern de facto standard.

Question 3

MD5

Answer 3

Hash - (Message Digest algorithm) Produces a 128-bit hash value output, expressed as a 32-digit hexadecimal.

Question 4

3DES

Answer 4

Symmetric Algorithm - A block cipher that uses a 168-bit key. 3DES (called triple DES) can use up to three keys in a multiple-encryption method.

Question 5

Diffie-Hellman

Answer 5

Asymmetric algorithm - Developed for use as a key exchange protocol, Diffie- Hellman is used in Secure Sockets Layer (SSL) and IPSec encryption.

Question 6

Two Fish

Answer 6

Symmetric Algorithm - A block cipher that uses a key size up to 256 bits.

Question 7

RC

Answer 7

Symmetric Algorithm - (Rivest Cipher) Encompasses several versions from RC2 through RC6. A block cipher that uses a variable key length up to 2,040 bits. RC6, the latest version, uses 128-bit blocks, whereas RC5 uses variable block sizes (32, 64, or 128).

Question 8

IDEA

Answer 8

Symmetric Algorithm - (International Data Encryption Algorithm) A block cipher that uses a 128-bit key.

Question 9

Blowfish

Answer 9

Symmetric Algorithm - A fast block cipher, largely replaced by AES, using a 64-bit block size and a key from 32 to 448 bits.

Question 10

Elliptic Curve Cryptosystem

Answer 10

Asymmetric algorithm - (ECC) Uses points on an elliptical curve, in conjunction with logarithmic problems, for encryption and signatures. Uses less processing power than other methods, making it a good choice for mobile devices.

Question 11

SHA-2

Answer 11

Hash - Developed by the NSA, actually holds four separate hash functions that produce outputs of 224, 256, 384, and 512 bits.

Question 12

El Gamal

Answer 12

Asymmetric algorithm - Not based on prime number factoring, this method uses the solving of discrete logarithm problems for encryption and digital signatures.

Question 13

DES

Answer 13

Symmetric Algorithm - A block cipher that uses a 56-bit key (with 8 bits reserved for parity); fixed blocked size.

Question 14

AES

Answer 14

Symmetric Algorithm - (Advanced Encryption Standard) A block cipher that uses a key length of 128, 192, or 256 bits, and effectively replaces DES.