#### Answer Description

PKI, or Public-Key-Infrastructure uses asymmetric encryption. There is a public key, and a private key, anything encrypted with a key can only be decrypted with the opposing key.

#### Wikipedia

Public key cryptography, or asymmetric cryptography, is any cryptographic system that uses pairs of keys: public keys which may be disseminated widely, and private keys which are known only to the owner. This accomplishes two functions: authentication, which is when the public key is used to verify that a holder of the paired private key sent the message, and encryption, whereby only the holder of the paired private key can decrypt the message encrypted with …

Public-key cryptography - Wikipedia, the free encyclopedia