IDEA stands for the International Data Encryption Algorithm. IDEA is a symmetric-key block cipher. It is denoted the same key can be used to encrypt the plaintext and decrypt the ciphertext.IDEA needed both the encrypting and decrypting parties to have a secret key that is different from a public-key and other asymmetric encryption schemes. The secret key popular to the encrypting party.IDEA is a patented and universally accessible block encryption algorithm, which allows the effective protection of transmitted and stored information against unauthorized access by third parties.The fundamental element for the development of IDEA were military durability for all security ... Read More

IDEA is a block cipher and it operates on 64bit plaintext and 128 bit key. IDEA is reversible like DES that is, the equivalent algorithm can be used for encryption and decryption. IDEA needs both diffusion and confusion for encryption.The 64-bit plaintext is divided into four portions of 16bit plaintext (P1 to P4). These are input to the first round. There are eight such rounds. The key includes 128 bits. In each round, six sub-keys are produced from the original key, each of these sub-key includes 16 bits.For the first round it can have key K1 to K6, for second ... Read More

IDEA stands for International Data Encryption Algorithm. IDEA is a block cipher invented by James Massey and Xuejia Lai and was first defined in 1991. It uses 128 bit key length which works on 64 bit blocks.It includes a series of eight identical transformations depend upon bitwise exclusiveor, addition and multiplication modules. It is based upon symmetric cipher and has very weak key design approach therefore security level of the algorithm is very underprivileged as compared to the DES. IDEA not becomes so much famous because of its complex structure.It is an IDEA, unlike the other block cipher algorithms is ... Read More

Blowfish is a symmetric block cipher algorithm invented by Brute Schneier in December 1993. The Blowfish algorithm has several advantages. It is applicable and efficient for hardware implementation and no license is needed. The elementary operators of Blowfish algorithm contains table lookup, addition and XOR. The table contains four S-boxes and a P-array.Blowfish is a cipher depends on Feistel rounds, and the design of the F-function used amounts to a simplification of the principles used in DES to support the same security with higher speed and effectiveness in software.Blowfish is a 64-bit symmetric block cipher that need a variable-length key ... Read More

Blowfish is a symmetric block cipher algorithm invented by Brute Schneier in December 1993. Blowfish is a substitute of DES or IDEA. One of the most popular feistel network ciphers is Blowfish. Blowfish algorithm has 64-bit block size and variable key length from 42 bits to 448 bits. The algorithm includes a key-expansion part, and data-encryption part.Blowfish create the key of at most 448 bits into several subkey arrays the total is 1042 32 bit values or 4168 bytes. It is a 16- round feistel system, which supports very high key-dependent S-boxes and enable 16 iterations.Every round is adapted with ... Read More

Blowfish is the symmetric block cipher algorithm and it encrypts the block information of 64-bits at a time. It follows the Feistel network and the working procedure of this algorithm is divided into two parts.Subkey Generation − This process transform the key upto 448 bits long to subkeys adding 4168 bits.Data-Encryption − In the data encryption process, it will iterate 16 times of network. Each round includes the key-dependent permutation, and the keyand data- dependent substitution. The operations in the algorithms are XORs or additions on 32-bit words. The only additional operations are four indexed array information lookups per round.Let ... Read More

The Blowfish encryption algorithm is a symmetric block cipher designed to achieve in the DES algorithm that was slow and uncertain. Blowfish is a keyed, symmetric cryptographic block cipher invented by Bruce Schneier in 1993 and located in the public domain.Symmetric encryption uses an individual encryption key to both encrypt and decrypt information. The sensitive information and the symmetric encryption key are used within the encryption algorithm to turn the sensitive information into ciphertext. Blowfish is contained in a huge number of cipher suites and encryption products, such as SplashID.A block cipher is generally a computer routine that takes some ... Read More

The strength of DES is as follows −Use of 56 bit keys56 bit key can be frequently used in encryption. There are 256 possible keys. A brute force attack on such number of keys is impossible.A machine implementing one DES encryption per microsecond would take more than thousands of years to divide the cipher.The assumption of one encryption per microsecond is excessively moderate. Diffie and Hellman postulated that the technology existed to develop a parallel machine with one million encryption equipment, each of which can implement one encryption per microsecond.It is necessary that there is more to key-search attack than ... Read More

There are some popular examples of Block Cipher which are as follows −The CAST Block Cipher − The CAST Block Cipher is an advancement of the DES block cipher, introduced in Canada by Carlisle Adams and Stafford Tavares. The name of the cipher appear to be after the initials of the inventors. The CAST algorithm has 64 bit block size and has a key of size 64 bits.CAST is based on the Feistel structure to perform the substitution permutation network. The authors defines that they need the Feistel mechanism, as it is well considered and free of basic structural weaknesses.Blowfish ... Read More

Weaknesses in Cipher Design − Some weaknesses that have been discovered in the design of cipher are as follows −S-boxes − There are three weaknesses have been discovered in S-boxes which are as follows −In S-box 4, the last three output bits can be changed in the same method as the first output bit by integrating some of the input bits.Two particularly chosen inputs to an S-box array can generate the same output.It is possible to acquire the same output in an individual round by converting bits in only three neighboring S-boxes.D-boxes − One mystery and one weakness were discovered ... Read More