Stegocrypto -A Review Of Steganography Techniques Using Cryptography (original) (raw)

The information security has become essential part of today's world due to extensive use of internet. The privacy of secret data can be achieved with two classical methods of data security namely Cryptography and Steganography.Cryptography results in scrambling of data into cipher text which is in unreadable or in nonexplainatory form, difficult to be guessed by eavesdropper, Steganography on the other hand hides the secret data into carrier medium in such a way that its detection is prevented.Steganography is not a replacement of cryptography but can supplement it to produce good results. It is observed that steganography alone is not sufficient for information security, so we can make more secure and robust approach by combining the best of steganography and cryptography. This paper describes the various steganographic techniques combined with cryptography. Since ancient times secure communication and hiding the secret messages is being an area of interest, steganography is a Greek word which means hiding the secrets. In ancient time this secure communication was achieved into different ways such as using invisible ink, or wax for secret message sharing. Roman people used to tattoo the messages on shaved head, once the hair grew slave was sent to deliver secret messages. Chinese people used to write on silk material and then this material is crunched into wax which is then swallowed [1].On the other hand cryptography is not concerned with message hiding instead it deals with changing the meaning and appearance of message. Cryptography changes the plain text into cipher text by the process of encryption; it uses the mathematical techniques for securing the information. Cryptography uses various encryption algorithms such as public key cryptography, private key or symmetric and asymmetric algorithm. The process of converting secret message into cipher text is called as encryption whereas process of converting cipher text into original message is called decryption. Cryptanalysis is the reverse process of cryptography with the intention of finding original message. II. CRYPTOGRAPHY The process of transferring plaintext into unreadable cipher text is called cryptography. While for transferring the data from one place to another in secured manner various cryptographic techniques are used depending upon the type of encryption algorithm. The public key algorithm uses two keys for communication while private key algorithm uses only one key for sending and receiving of the messages. The integrity, authentication, confidentiality and non repudiation of data should be maintained for successful transmission and reception of data. Data should be protected against eavesdropping, modification, fabrication and alteration. Cryptography is generally composed of the sender, plaintext, key, encryption algorithm, ciphertext and receipient.Two basic process of cryptography are encryption and decryption as shown in Fig.1 and Fig.2