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Budget du projet
$30 - $250 USD
Nombre total d'offres
26
Description du projet

TripleSDES

The DES algorithm uses keys of length 56 bits, which, when DES was originally designed, was thought to be secure enough to meet most needs. However, the increase in computing power makes it more tractable to brute-force crack a 56-bit key. Thus, an alternative version of DES using longer keys was desirable. The result, known as Triple DES uses two 56-bit raw keys k1 and k2 and is implemented by composing DES with itself three times in the following way:

E3DES(p) = EDES(k1,DDES(k2,EDES(k1, p)))

Here, p is the plaintext to encrypt, EDES is the usual DES encryption algorithm and DDES is the DES decryption algorithm. This strategy doubles the number of bits in the key, at the expense of performing three times as many calculations. This approach was shown to offer only the security of a 57-bit key rather than 112 bits as you might expect.)

The TripleDES decryption algorithm is just the reverse:

D3DES(c) = DDES(k1,EDES(k2,DDES(k1, c)))

For this part of the project, implement a class called TripleSDES that provides the following methods and calculates the TripleSDES encryption.

public static byte[] Encrypt( byte[] rawkey1, byte[] rawkey2, byte[] plaintext )

public static byte[] Decrypt( byte[] rawkey1, byte[] rawkey2, byte[] ciphertext )

Compétences requises

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