Best Answer

The reasoning for the Feistel cipher, as shown in Figure 3.6 applies in the case of

DES. We only have to show the effect of the IP and IP-1 functions. For encryption,

the input to the final IP-1 is RE16 LE16. The output of that stage is the ciphertext.

On decryption, the first step is to take the ciphertext and pass it through IP. Because

IP is the inverse of IP-1, the result of this operation is just RE16 LE16, which is

equivalent to LD0 RD0. Then, we follow the same reasoning as with the Feistel

cipher to reach a point where LE0 = RD16 and RE0 = LD16. Decryption is completed

by passing LD0 RD0 through IP-1. Again, because IP is the inverse of IP-1, passing

the plaintext through IP as the first step of encryption yields LD0 RD0, thus

showing that decryption is the inverse of encryption.

Q: Show that DES decryption is inverse of DES encryption?

Write your answer...

Submit

Still have questions?

Continue Learning about TV & Celebs

Des Hommes et Des Dieux was released on 02/25/2011.

Des Coleman was born on March 14, 1969.

Der Ring des Nibelungen was created in 1876.

Der Tag des Gerichts was created in 1762.

The cast of Des Bishop Live at Vicar Street - 2005 includes: Des Bishop as himself

Related questions

fot the past 25 years single des algorithm was used. But now triple des is used in atm cards for the encryption and decryption.

DES stands for Data Encryption Services which uses encryptrion or decryption services in which the sender & reciever share a single common key to encrypt or decrypt the message.

DES is a symmetric cryptographic algorithm, while RSA is an asymmetric (or public key) cryptographic algorithm. Encryption and decryption is done with a single key in DES, while you use separate keys (public and private keys) in RSA. DES uses 56-bit keys for encryption while RSA uses 2600-bits of KEY

3 DES of (Triple Data Encryption Standard)

DES

Data Encryption Standard. The related link will give you more information

DES Data Encryption Standard 56 bit

For some time it has been common practice to protect and tansport a key for DES encryption with triple-DES (3DES). The function follows an encrypt-decrypt-encrypt (EDE) sequence. Decrypt sequence is simply the same (encrypt) operation with the keys reversed.

DES is a widely-used method of data encryption using a private key that was judged so difficult to break by the U.S. government that it was restricted for exportation to other countries. There are 72,000,000,000,000,000 (72 quadrillion) possible encryption keys that can be used. For each given message, the key is chosen at random from among this enormous number of keys.

The primary cryptographical techniques employed when producing ciphertext are:HashingSymmetric encryptionAsymmetric encryption

These days, the use of DES is not recommended due to the short length of the key. In the past, the advantage was that the encryption made your information confidential unless you had the unlock key.In today's environment, DES is easily crackable. Going towards the use of AES, or 3DES, would be more desirable.

The duration of The Des O'Connor Show is 3600.0 seconds.