Cryptography techniques need some algorithms for encryption of data. Many of available
encryption techniques are used for textual data, a few of encryption methods are used for
multimedia data; however, this algorithms that are used for textual data may be inefficient for
multimedia. The most popular symmetric key algorithms are Data Encryption Standard
(DES). However, DES may not be suitable for multimedia because it consumes times.
Encryption and decryption of these data require different methods. This paper proposes an
encryption and decryption of data by using the nature of Fractional Fourier Transform (FrFT)
in signals analysis, based on multi-order FrFT. A different indicators to evaluate the security
of an encryption technique have been discussed. These indicators are: sensitivity proposed
techniques for the key, the complexity of the processes, and statistical analysis. The key is
formed by combination of order of FrFT. The encrypted data is obtained by the summation of
different orders. Numerical simulation results are given to demonstrate this proposed method.