Comparison of Cypher Methods

 

Ciphers implement encryption algorithms that allow for the hiding of messages and data behind seemingly random strings of characters.

In cryptography, encryption is the process of encoding messages or information in such a way that only authorized parties can read it. Encryption doesn't prevent hacking but it reduces the likelihood that the hacker will be able to read the data that is encrypted.In an encryption scheme, the message or information, referred to as plaintext, is encrypted using an encryption algorithm, turning it into an unreadable ciphertext This is usually done with the use of an encryption key, which specifies how the message is to be encoded. Any unauthorized agent that can see the ciphertext should not be able to determine anything about the original message. An authorized agent, however, is able to decode the ciphertext using a decryption algorithm that usually requires a secret decryption key that unauthorized agents do not have access to. For technical reasons, an encryption scheme usually needs a key-generation algorithm to randomly produce keys.

 

 

Cypher Algorithm

 

Key Size

Block Size

Security

AES_128

128 bits

 

128 bit
  • Most secure

AES_192

192 bits

 

128 bit
  • Most secure

AES_256

256 bits

 

128 bit
  • Most secure

TRIPLE_DES

 

128 bits
or 168 bits
or 192 bits

 

(168 bits used by this application.)

64 bits
  • Less secure than AES
  • More secure than DES
  • OpenPgp Library used by this application uses 168 bit cipher involving three applications of the DES algorithm.

 

DES (Data Encryption Standard)

64 bits

64 bits
  • Old technology
  • Least secure

 

CAST5

(aka CAST-128)

40 to 128 bits

(in 8 bit increments)

 

(128 bits used by this application.)

64 bits
  • Default for some versions of PGP and GPG.
  • Very secure.
  • Smaller block size reduces security compared to AES.

 

BLOWFISH

 

32 to 448 bits

64 bits
  • Has been replaced by TWOFISH
  • Believed secure except for block size.
  • Intended to be better than DES.

 

TWOFISH

 

128, 192 or 256 bits

 

(256 bits used by this application.)

128 bits
  • Similar to AES in terms of security and speed.
  • Slightly slower than AES_128.
  • Somewhat faster than AES_256.
  • Less efficient than AES in memory usage.

 

SAFER

 

40, 64 or 128 bits

 

64 bits
  • Not used much compared to other encryption algorithms

 

IDEA

 

128 bits

64 bits
  • Intended as a replacement for DES