Dual Encryption by Random Segmentation and Random Re-Arrangement (RSRA) using Two Dimensional Array Er. Amit Kumar (Scholar), Dr. Jayant Shekhar (Professor), Subharti Institute of Technology and Engineering, Swami Vivekanand Subharti University, Meerut Abstract—Cryptography is a method of storing and transmitting data in a particular form so that only those for whom it is intended can read and process it. Cryptography includes techniques such as microdots, merging words with images, and other ways to hide information in storage or transit. However, in today's computer-centric world, cryptography is most often associated with scrambling plaintext (ordinary text, sometimes referred to as cleartext) into ciphertext (a process called encryption), then back again (known as decryption). Individuals who practice this field are known as cryptographers. To make a secure and successful transaction of message, the security of cipher text is must before transmission over communication channel. This paper propose a new encryption technique with the help of random segmentation and random re-arrangement of cipher text using two dimensional array before transmission over communication channel so that the transmitted cipher text is more complex to decrypt by any attacker. Index Terms—Crptography, Symmetric encryption, Asymmetric encryption, Cryptanalysis, Cipher text, AES, DES, Dual encryption, RSA, ECC, Adaptive chosen-plaintext, Related-key attack, Private Key, Public Key, Secret Key. I. INTRODUCTION Until modern times, cryptography referred almost exclusively to encryption, which is the process of converting ordinary information (called plaintext) into unintelligible text (called ciphertext). Decryption is the reverse, in other words, moving from the unintelligible ciphertext back to plaintext. A cipher (or cypher) is a pair of algorithms that create the encryption and the reversing decryption. The detailed operation of a cipher is controlled both by the algorithm and in each instance by a "key". The key is a secret (ideally known only to the communicants), usually a short string of characters, which is needed to decrypt the ciphertext. Formally, a "cryptosystem" is the ordered list of elements of finite possible plaintexts, finite possible cyphertexts, finite possible keys, and the encryption and decryption algorithms which correspond to each key. Keys are important both formally and in actual practice, as ciphers without variable keys can be trivially broken with only the knowledge of the cipher used and are therefore useless (or even counter-productive) for most purposes. Historically, ciphers were often used directly for encryption or decryption without additional procedures such as authentication or integrity checks. II. LITERATURE REVIEW Modern encryption methods can be divided by two criteria: by type of key used, and by type of input data. 1. By type of key used ciphers are divided into: 1.1 Symmetric key algorithms (Private-key cryptography) In symmetric systems the same key (the secret key) is used to encrypt and decrypt a message. Data manipulation in symmetric systems is faster than asymmetric systems as they generally use shorter key lengths. Symmetric models include the commonly used AES (Advanced Encryption Standard) which replaced the older DES (Data Encryption Standard). (Figure 1.1 : Symmetric-key cryptography, where a single key is used for encryption and decryption) 1.2 Asymmetric key algorithms (Public-key cryptography) Asymmetric systems use a public key to encrypt a message and a private key to decrypt it. Use of asymmetric systems enhances the security of communication. Examples of asymmetric systems include RSA (Rivest-Shamir- Adleman), and ECC (Elliptic Curve Cryptography). (Figure 1.2 : Public-key cryptography, where different keys are used for encryption and decryption) Amit Kumar et al, / (IJCSIT) International Journal of Computer Science and Information Technologies, Vol. 7 (5) , 2016, 2158-2162 www.ijcsit.com 2158