In addition to controlling access, the firewall can provide extra security for sensitive data. Because the firewall can identify the hosts and applications to which a packet belongs, it can provide additional security through encryption. The encrypted packet will be decrypted in the firewall once it reaches its destination. Using this feature, sensitive information, such as student records, financial data, or personnel data, can travel over the network and be secure even if intercepted. The solution most often offered to insure privacy of information is encryption.
Encryption involves the scrambling of data through a hardware or software embedded algorithm.
The information passes through the network in this encrypted form and is decrypted via a similar mechanism once it arrives at its designated destination. Encryption standards have existed since the mid 1970s and are widely available and utilized throughout the data communications industry. While encryption products do offer a high level of security from data being monitored as it is transported through the network, their implementation does impact several financial, maintenance, and performance issues. Some encryption schemes can prove quite costly, especially in light of the opportunity costs involved in implementing networks in schools. For example, a school might find itself choosing between allocating budget to either a sophisticated encryption product or installing higher bandwidth connectivity or systems in the classroom.