Stream Cipher with Space-Time Block Code

This paper proposes a new method to secure data in the physical layer (physical layer cipher) in mobile networks using a cipher with channel code (space-time block code or STBC), which is used to increase reliability in wireless networks. In this method, we will cipher the STBC codewords and use a new approach to produce keys related to arithmetic attributes of images as an average value. There is no requirement to insert any major key by the user. In this method, the average value of the packet is used as a seed for the linear feedback register (LFSR). Then, it will generate keys as complex forms that are used to cipher STBC codewords; the results practically and theoretically show a stronger method against plain attackers, knownplaintext attacks, choice plaintext attackers, and ciphertext attackers and creates more confusion and diffusion to make cipher analysis more difficult. Their effect on security is discussed. Performance, system architecture, and the proposed method satisfy the performance analysis tests (of the image), such as the histogram, power spectrum, correlation, large key space, NPCR, UACI, and entropy, and it is resistant to statistical, brute force, and differential attacks.