An Efficient Encryption Algorithm for Perfect Forward Secrecy in Satellite Communication

Satellite communication is among those applications where data confidentiality is required, but at the same time, computational resources are limited as well as the delay is critical. For these types of applications, symmetric key encryption algorithms are preferred over asymmetric key algorithms, due to lower computational cost and faster speed of operation. Furthermore, due to various critical aspects of information security, using Perfect Forward Secrecy (PFS) in many communication applications is advantageous. There are two ways to achieve PFS; either a mechanism for new key generation is required, or some protocols are used for sharing new session keys before communication. Both of these ways, at minimum, append additional computational load and delay in communication, which are critical in satellite communication. This is probably the most significant barrier that satellites do not use PFS for every communication. This paper presents a novel encryption algorithm where a message key is generated such that later only Exclusive OR (XOR) operation can be used to produce the ciphertext. Hence, the proposed algorithm eliminates the need for two separate algorithms for message key generation and encryption for PFS. Security analysis and experimental results show that proposed encryption algorithm is not only secure but also faster and cheaper than the widely used AES-CTR encryption algorithm. Therefore it is suitable to be used in satellite communication for PFS.