Tuesday, 12 June 2018

CAIIB IT

caiib IT

CRYPTOGRAPHY
There are two basic types of Encryption algorithms:
(i) Symmetric encryption
(ii) Asymmetric Encryption
Symmetric Encryption: In this encryption technique the sender and receiver encrypts and decrypts the message with the same key. Examples are Twofish, Serpent, AES (Rijndael), Blowfish, CAST5, Kuznyechik, RC4, 3DES, Skipjack etc.

Asymmetric encryption: In this encryption technique the sender encrypts the message with the receiver’s public key and the receiver decrypts the information with recipient’s private key. Hence this technique is called public key encryption. Examples are: Diffie-Hellman, RSA, ECC, ElGamal, DSA etc.

Among the various models of symmetric cipher analyzed the Rijndael is the best. Actually it is the role model of DES and AES. This model is adopted by different information security agencies like NSA, NIST and FIPS.
Among the various asymmetric ciphers, RSA is a moderate and most useful cipher for small data encryption like digital signature, ATM Pin etc.
But as discussed above, RSA (asymmetric technique) is much slower than Rijndael (symmetric technique) and other symmetric cipher techniques. But the scalability of asymmetric cryptosystem is far higher than the symmetric cryptosystem. Thus where the number of users is huge and required keys are very high, asymmetric cryptosystem proves to be superior.
It is scientifically predicted that the symmetric cipher like Rijndael is supposed to be secure against mathematical attacks until 2090. Thus they are very suitable for hardware level security in communicating devices.
Advanced Encryption Standard (AES): is the successor of DES (Data Encryption Standard) as standard symmetric encryption algorithm for US federal organizations. AES uses keys of 128, 192 or 256 bits, although, 128 bit keys provide sufficient strength today. It uses 128 bit blocks, and is efficient in both software and hardware implementations. It was selected through an open competition involving hundreds of cryptographers during several years.
Safe Key Length
128-bit encryption is a data/file encryption technique that uses a 128-bit key to encrypt and decrypt data or files. In today’s parlance, it is considered one of the most secure encryption methods and used in most modern encryption algorithms and technologies. 128-bit encryption is considered to be logically unbreakable as of date. However, it is to be remembered that breakability is only relative considering the technology available at that time. Keeping this in view, it is also recommended by many that the cipher AES-256 be used among other places in SSL/TLS across the Internet. It's considered among the top ciphers. In theory it's not crackable since the combinations of keys is massive.

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