First of all, with symmetric encryption, the message is encrypted and decrypted with the same secret key. This poses two problems: 1) Distribution of the secret key and 2) Secure storage of the secret key.
Asymmetric encryption is different from symmetric encryption since one key is used to encrypt the message and another key is used to decrypt the message. It solves problem #2, bur still has problem #1. One example of asymmetric encryption is public key encryption. The public key is used to encrypt the message and the private key is used to decrypt the message. The receiver would have to generate a private and public key. Then in order to receive data, they would have to have a way of publishing the public key. Maybe the public key could be copied onto a memory stick and mailed to the key server. Maybe the public key can be published at an Internet site, etc. Either way, it’s not nearly as smooth as could be.
–Konrad Roeder, WA4OSH