A Novel Latin Square Image Cipher

In this paper, we introduce a symmetric-key Latin square image cipher (LSIC) for grayscale and color images. Our contributions to the image encryption community include 1) we develop new Latin square image encryption primitives including Latin Square Whitening, Latin Square S-box and Latin Square P-box ; 2) we provide a new way of integrating probabilistic encryption in image encryption by embedding random noise in the least significant image bit-plane; and 3) we construct LSIC with these Latin square image encryption primitives all on one keyed Latin square in a new loom-like substitution-permutation network. Consequently, the proposed LSIC achieve many desired properties of a secure cipher including a large key space, high key sensitivities, uniformly distributed ciphertext, excellent confusion and diffusion properties, semantically secure, and robustness against channel noise. Theoretical analysis show that the LSIC has good resistance to many attack models including brute-force attacks, ciphertext-only attacks, known-plaintext attacks and chosen-plaintext attacks. Experimental analysis under extensive simulation results using the complete USC-SIPI Miscellaneous image dataset demonstrate that LSIC outperforms or reach state of the art suggested by many peer algorithms. All these analysis and results demonstrate that the LSIC is very suitable for digital image encryption. Finally, we open source the LSIC MATLAB code under webpage https://sites.google.com/site/tuftsyuewu/source-code.Comment: 26 pages, 17 figures, and 7 table

Secure Communication using Identity Based Encryption

Secured communication has been widely deployed to guarantee confidentiality and\ud integrity of connections over untrusted networks, e.g., the Internet. Although\ud secure connections are designed to prevent attacks on the connection, they hide\ud attacks inside the channel from being analyzed by Intrusion Detection Systems\ud (IDS). Furthermore, secure connections require a certain key exchange at the\ud initialization phase, which is prone to Man-In-The-Middle (MITM) attacks. In this paper, we present a new method to secure connection which enables Intrusion Detection and overcomes the problem of MITM attacks. We propose to apply Identity Based Encryption (IBE) to secure a communication channel. The key escrow property of IBE is used to recover the decryption key, decrypt network traffic on the fly, and scan for malicious content. As the public key can be generated based on the identity of the connected server and its exchange is not necessary, MITM attacks are not easy to be carried out any more. A prototype of a modified TLS scheme is implemented and proved with a simple client-server application. Based on this prototype, a new IDS sensor is developed to be capable of identifying IBE encrypted secure traffic on the fly. A deployment architecture of the IBE sensor in a company network is proposed. Finally, we show the applicability by a practical experiment and some preliminary performance measurements