Information | Network Security | Cryptography | Symmetric and ASymmetric Cryptography | Lecture 5

Information or network security play very important role in digital world. Everything is moving toward online systems and for this security is very important role for success of this system. We use different security mechanism to protect the system. Examples of common security mechanisms are as follows Cryptography, Message digests and digital signatures ,Digital certificates ,Public Key Infrastructure (PKI) In this lecture we discuss cryptography in detail. Cryptography is the process of writing something secret. if we want to store or transfer data in secure form, we use cryptography. cryptography is very important aspect of security mechanism. In network security or information security system must used cryptography for secure data transfer and achieve confidentiality. When we want to send any mess to receiver our original text for example “cryptography” is called plain text through crypto algorithms plain text changed for example cryptography to “apfdfjjgdddfd” is called cipher text and this procedure is called encryption. Cryptanalysis is the science of braking and analyzing the cipher. cryptology covers both subject. There two basic categories of cryptography “symmetric “and “asymmetric” encryption in symmetric we use single key for both encryption and decryption while asymmetric use two different keys.in this lecture we discuss symmetric encryption in detail.in symmetric encryption we discuss block cipher and stream cipher. Block cipher algorithms use block of characters or block of bits to encrypt and decrypt the data. There are different algorithms of block cipher for example DES, triple des and AES they use block cipher and use 64-bit block for encryption. encryption algorithms uses any key to encrypt or decrypt the data. Different algo uses different size of key for example des use 56-bit key size triple des use 112- or 128-bit key size AES use 256-bit key size. block cipher encryption is easy and decryption is little bit difficult as compare to stream cipher. Stream cipher process continuously input because its uses 8 bit mean one-byte ore one character at a time and produces one-byte output.so encryption is little bit difficult but decryption is easy as compare to block cipher. Cryptography offered many Services like. Data Confidentiality, Data Integrity, Data Origin Authentication, Confidentiality, Symmetric Encryption, Asymmetric Encryption, Integrity, Hash Function, Data Origin Authentication and Digital Signatures. There are also many practical security issues for example Every Encryption Algorithm is prone to Brute Force Attack – Computationally Secure Algorithm is required. Brute-force Attack: is to try every possible key on a piece of ciphertext until an intelligible translation into plaintext is obtained. In this important lecture we try our best to explain the things don’t worry if any issue contact with us we are here to help you guide you. stay tuned with techno learn. #NetworkSecurity #Cryptography