Leading Protocols

The following are some leading protocols that are used for secure data transmission.

Secure Sockets Layer (SSL)

SSL is the dominant security protocol being used on the Internet today. It was developed by Netscape to provide secure and private Internet sessions, typically on top of HTTP, although it can also be used over FTP and other relevant protocols. SSL uses a combination of symmetric and asymmetric algorithms to maximize performance.

There are four phases in an SSL session:

1. Handshake and cipher negotiation. Both the client and server agree on the algorithms or ciphers to use.
2. Authentication. The server, and optionally the client, is authenticated using digital certificates.
3. Key exchange. The client creates a secret key and sends it to the server using its public key for encryption. The server decrypts the message using its private key; and for the remainder of that session, the client and server can communicate using the secret key.
4. Application data exchange. Once the secure symmetric session has been established, encrypted data can be communicated between the client and the server.

SSL can be used by many of the more powerful wireless clients, including laptops and Pocket PC devices. You can tell you are using SSL when the URL starts with https://, rather than just http://.

Encrypting the data within the protocol is more efficient than encrypting the data yourself and sending it over HTTP. Within the SSL protocol, the data will be encrypted on a packet level and can be decrypted on a packet level after it has arrived and has passed any sort of integrity test. If you encrypt your data as one large cipher text, then you will not be able to decrypt the data until all the packets have arrived.