Public key cryptography is a cryptographic technique which uses public key and private key for encryption and decryption of the message that is to be sent over the network.
Rather than using a single key for both encrypting and decrypting the message, Public key Cryptography uses separate keys namely public key and private keys for the encryption and decryption of messages thereby adding additional security during the transfer of messages.
People can use Public key cryptography also known as asymmetric cryptography for securely performing transactions over the network and also to prove their identity on the network for validating the transactions.
Public key is the cryptographic key that is usually shared openly without any restriction for access whereas the private key is not usually shared openly and is kept a secret by the owner of the transaction as it acts as the password that is needed for a transaction to be successful.
The combination of both these keys create a digital signature. A digital signature is a digital code which is generated and authenticated by public key encryption, which is attached to an electronically transmitted document to verify the sender’s identity and also to verify its contents. Digital Signatures are digital form of signatures that use mathematical functions for authenticating a transaction. For authenticating a transaction, one must solve the mathematical function encrypted into the digital signature that is associated with that respective transaction thereby preventing false claims regarding the ownership of the transaction and impersonations of the wallets from which the transactions are processed.
The main purpose of using private and public key cryptography in block chain technology is to ensure safe transactions over the block chain network. The use of a single public key for doing transactions over the internet may be dangerous as if the public key is obtained by illegal people , they can proceed to do illegal and unauthorized transactions on the block chain network without the knowledge of the wallet owner. But, when the combination of both public and private keys are used for encrypting and decrypting the transactions that are done over the block chain network as the transaction can be decrypted only when the private key of the transaction is revealed by the owner and cannot be decrypted only with the help of public key. Since the private key is usually kept secret, and is revealed only when the recipient’s and sender’s identities and the transaction is verified, there is no probability of the details falling into illicit hands and any fraud taking place thus securing the block chain network and ensuring safe and secure transactions.