What are the application of Public Key Cryptosystem in Information Security?

Public key cryptography is called as asymmetric key cryptography. It is an essential encryption and decryption pattern in online software. It uses two different keys termed as public key and private key.

In symmetric key algorithms, only one key is used to implement encryption and decryption operations. But in public key cryptography, there are two keys are used to implement encryption and decryption operations. If one key is used to implement encryption operation, and second key is used to perform decryption operation vice versa.

The keys generated in public key cryptography are large including 512, 1024, 2048, etc., bits. These keys are not simply to learn. Thus, they are maintained in the devices including USB tokens or hardware security modules.

The asymmetric cryptosystem should achieve the security services including confidentiality, authentication, integrity and non-repudiation. The public key should support the security services including non-repudiation and authentication. The security services of confidentiality and integrity treated as an element of encryption process completed by secret key of the user.

Public key systems are featured by the need of cryptographic algorithm with two keys, one held private and one accessible publicly. It is based on the application, the sender uses the sender’s private key or the receiver’s public key, or both to implement some type of cryptographic algorithm.

The use of public key cryptosystem is defined into three elements which are as follows −

  • Encryption/Decryption − The sender encrypts a message with the receiver public key.

  • Digital Signature − The sender signs a message with its secret key. Signing is completed by a cryptographic algorithm used to the message or to a smaller block of information that is a function of the message.

  • Key Exchange − There are two sides agree to exchange a session key. There are multiple approaches are possible including the private key of one or both parties.

There are the essential steps for public key cryptosystem are as follows −

  • Each user generates a set of keys to be used for the encryption and decryption of messages.

  • Each user establish one of the two keys in a public register or other available file. The component key is maintain private. Each user supports a set of public keys acquired from others.

The main applications of Public key cryptosystem are Digital Signatures and Data Encryption. Digital signatures are the public-key primitives of message authentication. In the matter, it is general to use handwritten signatures on handwritten or typed messages.

The encryption application supports the confidentiality and integrity security services for the information. The public key supports the security services including authentication and non-repudiation.