What is a Cryptosystem in Information Security?

A cryptosystem is also called a cypher system. It implements cryptographic techniques using several cryptographic components including plain text, encryption algorithm, cypher text, decryption algorithm, and encryption key to support information security services.

A cryptosystem is a set of algorithms such as one for the encryption of data and another for decryption. In these algorithms, it can use a unique key that must be kept secret, and in which case the process for making and sharing the key is also considered an element of the cryptosystem.

Cryptanalytic attacks based on the feature of the algorithm added possibly some knowledge of the general features of the plaintext or even some sample plain textcipher text pairs. This type of attack exploits the feature of the algorithm to attempt to understand a definite plaintext or to understand the key being used.

Modern cryptography is important to the digital world and it can live in and has grown to be quite difficult. It can be used for sending messages in a secure manner on the internet, including the credit card information and other private information.

Encryption is used to maintain the data secure online and locally. The Advanced Encryption Standard (AES) is used by governments to support the secrecy of their files and was chosen from a number of students across the mathematics community for its security and effectiveness.

Moreover, digital security can also be used to support anonymity, to authenticate one’s identity through digital signatures. It can demonstrate a proof of work in blockchain technologies and to provide that application and messages are free from tampering.

There are various features of cryptosystem which are as follows −

  • The type of operations used for transforming plaintext to cipher text − All encryption algorithms are based on two general principles such as substitution, in which each component in the plaintext (bit, letter, group of bits or letters) is mapped into another component, and transposition, in which component in the plaintext are rearranged.

    The central requirement is that no data be lost (that is, that all operations are changeable). Most systems, defined as product systems, include several stages of substitutions and transpositions.

  • The number of keys used − If both sender and receiver use the similar key, the system is defined as symmetric, single-key, secret-key, or conventional encryption. If the sender and receiver use multiple keys, the system is defined as asymmetric, twokey, or public-key encryption.

  • The way in which the plaintext is processed − A block cipher processes the input one block of component at a time, creating an output block for each input block. A stream cipher processes the input component continuously, creating output one component at a time, as it goes along.

Updated on: 11-Mar-2022


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