Differential Cryptanalysis: It is one of the most significant recent (public) advances in cryptanalysis which known by NSA in 70’s cf DES design by Murphy, Biham & Shamir published 1990. It is one of the most powerful method to analyse Read More …

# Category: Engineering Notes

Engineering Notes

## Explain the principle of Steganography in brief. Differentiate between steganography and cryptography?

Steganography deals with composing hidden messages so that only the sender and the receiver know that the message even exists. Since nobody except the sender and the receiver knows the existence of the message, it does not attract unwanted attention. Read More …

## Explain how symmetric encryption is performed and write down its step?

An encryption scheme has five ingredients: Plaintext: This is the original message or data that is fed into the algorithm as input. Encryption algorithm: The encryption algorithm performs various substitutions and transformations on the plaintext. Secret key: The secret key Read More …

## Cryptography and Cryptanalysis is an important aspect of network security, Comment?

Cryptography: Cryptographic systems are generically classified along three independent dimensions: The type of operations used for transforming plaintext to cipher text: All encryption algorithms are based on two general principles: substitution, in which each element in the plaintext (bit, letter, Read More …

## DES is not a block cipher method of encryption method. State true or false and explain DES?

False, DES is a block cipher method. The most commonly used symmetric encryption algorithms are block ciphers. A block cipher processes the plaintext input in fixed-sized blocks and produces a block of cipher text of equal size for each plaintext Read More …

## Discuss S-Boxes in DES, its Strength and Triple DEA?

It has eight S-boxes which map 6 to 4 bits and each S-box is actually 4 little 4 bit boxes outer bits 1 & 6 (row bits) select one rows inner bits 2-5 (col bits) are substituted result is 8 Read More …

## Write short notes on ECB, CBC, CFM and CTR?

Symmetric block cipher processes one block of data at a time. In the case of DES and 3DES, the block length is b 64 bits; for AES, the block length is b 128 bits. For longer amounts of plaintext, it Read More …

## Write Diffie-Hellman key exchange algorithm?

The first published public-key algorithm appeared in the seminal paper by Diffie The purpose of the algorithm is to enable two users to exchange a secret key securely that then can be used for subsequent encryption of messages. The algorithm Read More …