[IDSTM: January 2017] ISSN 2348 – 8034 Impact Factor- 4.022 (C)Global Journal Of Engineering Science And Researches 86 GLOBAL JOURNAL OF ENGINEERING SCIENCE AND RESEARCHES REVIEW ON NETWORK SECURITY AND CRYPTOGRAPHIC TECHNIQUES Nupur Chugh, Ritu Kadyan, Abhinav Kanojia Assistant Professor, Department of Computer Science & Engineering, Scholar, Department of Computer Science & Engineering, Ganga Technical Campus, Soldha ABSTRACT Nowadays the applications like Internet and networks are growing very fast, thereby the importance and the value of the exchanged data over the internet or other media types are increasing. For secure communication the cryptography is essential, therefore we have various cryptography algorithms for securing the data over internet. This paper discuss the state of the art for a broad range of cryptographic algorithms that are used in networking applications. A comparison table is created for various cryptography algorithms used as per the requirement on different networks. Keywords-. Secret Key/ Symmetric Key Cryptography. Introduction One of the classic techniques used for ensuring privacy of files and communication is Cryptography is the science of secret writing so that the meaning of a message can be hidden.For securing the data different types of cryptography techniques are used to achieve the goals: secret key (or symmetric) cryptography, public-key (or asymmetric) cryptography. Secret Key/ Symmetric Key Cryptography In this type of cryptography a single key is used for encryption and decryption of data. Symmetric key ciphers are implemented as either blockciphers or stream ciphers.The Data Encryption Standard (DES) and Advanced Encryption Standard (AES) are examples of Secret Key Cryptography. Public Key/ Asymmetric Key Cryptography Asymmetric Key Cryptography use two keys, one is private key and the other is public key for encrypting and decrypting messages. A message that is encrypted by using the public key can only be decrypted by applying the samealgorithm and using the matching private key. Likewise, a message that is encrypted by using the private key can only be decrypted by using the matching public key. RSA, Diffie Hellman and ECC are examples of public key Cryptography. CRYPTOGRAPHY TECHNIQUES DES(Data Encryption Standard) DES (the Data Encryption Standard) is a symmetric block cipher developed by IBM.Goal of DES is to completely scramble the data and key so that every bit of cipher text depends on every bit of data and every bit of key. DES is widely used, despite claims that the key length is too short. Six different permutation operations are used both in key expansion part and cipher part. The DES weaknesses is recorded by many attacks and methods, which implies that it is an insecure block cipher.The following diagram shows the process of encryption and decryption using DES.