public key private key Cryptography

Public Key Cryptography

Public key cryptography is a security mechanism used to provide confidentiality and authenticity in information exchange by using cryptographic algorithms that work with public and private keys. These cryptographic algorithms are used to digitally sign documents, digital signature verification, and document encryption and decryption.

The public key is a number, which is usually bound to a person. A public key can be used for -

• check digital signatures, created with the corresponding private key,
• encrypting documents that can then be decrypted only by the owner of the corresponding private key. 

The public keys are not secret to anybody and are usually publicly available. The public key of a given person must be known to anyone communicating with the person using public key cryptography.

The private key is a number, known only to its owner. A private key can be used for -

• sign documents and 
• decrypt documents that are encrypted with the corresponding public key. 

Private keys are generally password protected and private to it's owner. Owner must not share this key to any one.

In next post you will see the procedure (commands) to create private public key pair using java keytool.