PROGRAMMER BABU

  Public-key or asymmetric-key encryption  algorithms   use a pair of keys, a public key associated with the creator/sender for encrypting messages and a private key that only the originator knows (unless it is exposed or they decide to share it) for decrypting that information. Examples of public-key cryptography include: RSA , used widely on the internet Elliptic Curve Digital Signature Algorithm (ECDSA) used by Bitcoin Digital Signature Algorithm (DSA) adopted as a Federal Information Processing Standard for digital signatures by NIST in FIPS 186-4 Diffie-Hellman key exchange To maintain data integrity in cryptography,  hash functions , which return a deterministic output from an input value, are used to map data to a fixed data size. Types of cryptographic hash functions include SHA-1 (Secure Hash Algorithm 1), SHA-2 and SHA-3. Cryptography concerns Attackers can bypass cryptography, hack into computers that are responsible for data encryption and decryption, and...

  Cryptographic algorithms Cryptosystems use a set of procedures known as cryptographic algorithms, or  ciphers , to encrypt and decrypt messages to secure communications among computer systems, devices and applications. A cipher suite uses one algorithm for encryption, another algorithm for message authentication and another for key exchange. This process, embedded in protocols and written in software that runs on operating systems (OSes) and networked computer systems, involves: public and private key generation for data encryption/decryption digital signing and verification for  message authentication key exchange Types of cryptography Single-key or symmetric-key encryption  algorithms  create a fixed length of bits known as a  block cipher  with a secret key that the creator/sender uses to encipher data (encryption) and the receiver uses to decipher it. One example of symmetric-key cryptography is the Advanced Encryption Standard ( AES ). AES is a ...

  Modern cryptography concerns itself with the following four objectives: Confidentiality.  The information cannot be understood by anyone for whom it was unintended. Integrity. The information cannot be altered in storage or transit between sender and intended receiver without the alteration being detected. Non-repudiation.  The creator/sender of the information cannot deny at a later stage their intentions in the creation or transmission of the information. Authentication.  The sender and receiver can confirm each other's identity and the origin/destination of the information.

  Cryptography techniques Cryptography is closely related to the disciplines of  cryptology  and  cryptanalysis . It 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.

What is cryptography?   Cryptography is a method of protecting information and communications through the use of codes, so that only those for whom the information is intended can read and process it. In computer science, cryptography refers to secure information and communication techniques derived from mathematical concepts and a set of rule-based calculations called algorithms, to transform messages in ways that are hard to decipher. These deterministic algorithms are used for cryptographic key generation, digital signing, verification to protect data privacy, web browsing on the internet and confidential communications such as credit card transactions and email.