What are the advantages of public-key cryptography over secret-key cryptography?
The primary advantage of public-key cryptography is increased security and convenience: private keys never need to be transmitted or revealed to anyone. In a secret-key system, by contrast, the secret keys must be transmitted (either manually or through a communication channel) since the same key is used for encryption and decryption. A serious concern is that there may be a chance that an enemy can discover the secret key during transmission. Another major advantage of public-key systems is that they can provide digital signatures that cannot be repudiated.
