Symmetric - a single digital key will be used for encryption. and hence it will be fast. and the key will be shared between 2 parties. asymmetric - Will be used a key pair based encryption. a combination of public - private key pair, where private key can decrypt the data encrypted with corresponding public keys. and the Public key will be shared each other but private key kept secret. In other words, while sending, the data will be encrypted using receivers public key, and while receiving, the encrypted will be decrypted using private key.