Question

Cryptography***

Let’s assume you do DES double encryption by encrypting a plaintext twice with K1 and K2 respectively. Is this method more secure than the regular single DES encryption? Please explain your reason.

Answer 1

Data encryption standard (DES) uses 56 bit key to encrypt any plain text which can be easily be cracked by using modern technologies. To prevent this from happening double DES and triple DES were introduced which are much more secured than the original DES because it uses 112 and 168 bit keys respectively. They offer much more security than DES.

Double DES is a encryption technique which uses two instance of DES on same plain text. In both instances it uses different keys to encrypt the plain text. Both keys are required at the time of decryption. The 64 bit plain text goes into first DES instance which than converted into a 64 bit middle text using the first key and then it goes to second DES instance which gives 64 bit cipher text by using second key

Double encryption is not equivalent to single encryption. Security does increase by double encryption, but it does not increase much. The security of DES depends on its having a large key space