Wireless Data Security using Encryption and Frequency Hopping

Data Security is very important aspect for every communication system. One of the very popular techniques to assure the data security is encryption, where the transferred data is converted into cipher text. Also, protection against undesired interception while transmission process takes place is the key priority for secure reception of data. This feature is supported by spread spectrum techniques such as FHSS [1]. For FHSS, a bandwidth is divided into number of different distinct channels. The transmitter as well as receiver has to be synchronized on a particular channel and seed value to get a faithful output at the receiver. The transmitting section then transmits the message, broadcasting only for a few hundred milliseconds on any given channel. The transmitter then starts jumping (hopping) between different channels according to a pseudo-random algorithm (which is predefined by user); since the receiver knows the start channel and has exactly same seed, it can use the same algorithm to follow the hops and receive the signal. To any unauthenticated user who does not know the hopping sequence, the message is nearly indecipherable.