Asymmetric algorithms, on the other hand, use one key for encryption and another for decryption. The two keys are related in a mathematical sense. Yet, even if one of the keys is known, it is very hard to calculate the other. Asymmetric algorithms are popular because the keys can be published. This published key is known as the public key .
Public keys allow anyone to use the key to encrypt a message and send it to a recipient.
The only person who can decrypt the message is the recipient because the recipient is the only one who knows the other key, which is known as the private key . Hence, anybody can send an encrypted message, even people unknown to the recipient. The transmission of this secret key could be intercepted, removing any security. This limitation seems like a drawback, but in reality it doesn't much matter. In a situation where a recipient wants to allow anyone to send large amounts of data in a secure manner, using a symmetric algorithm may not be the best solution.