Recently, arithmetic coding has attracted the attention of many scholars because of its high compression capability. Accordingly, in this paper a method which adds secrecy to this well-known source code is proposed. Finite state arithmetic code (FSAC) is used as source code to add security. Its finite state machine (FSM) characteristic is exploited to insert some random jumps during source coding process. In addition, a Huffman code is designed for each state to make decoding possible even in jumps. Being Prefix free, Huffman codes are useful in tracking correct states for an authorized user when s/he decodes with correct symmetric pseudo random key. The robustness of our proposed scheme is further reinforced by adding another extra uncertainty by swapping outputs of Huffman codes in each state. Several test images are used for inspecting the validity of the proposed Huffman Finite State Arithmetic Coding (HFSAC). The results of several experimental, key space analyses, statistical analysis, key sensitivity and plaintext sensitivity tests show that HFSAC with a little effect on compression efficiency for image cryptosystem provides an efficient and secure way for real-time image encryption and transmission.
Secure Arithmetic Computation with No Honest Majority
我们研究了有限环上安全评估算术电路的复杂性。这个问题的动机是自然的安全计算任务。我们的主要目标是：（1）只对环操作和标准密码原语进行黑箱调用，（2）最小化此类黑箱调用的数量以及通信开销。我们提出了几种解决方案，其不同的效率，一般性和潜在的棘手的假设。这些措施包括：1. OT-混合模型中的无条件安全协议，其使用任意环$R$的黑盒，但是其中环操作的数量随着$\log|R|$（上界）线性增长。2. OT-混合模型中的计算安全协议，该模型使用底层环的黑盒，并且其中环操作的数量不随环的大小而增长。这些结果扩展了Naor和Pinkas用于安全多项式评估的先前方法（SIAM J. Comput.，35（5），2006）。3.环$\mathbb{Z}_m=\mathbb{Z}/m\mathbb{Z}$的一种协议，它只使用同态加密方案的黑盒。当$m$是素数时，电路的每个门对加密方案的调用（分摊）次数是恒定的。事实上，我们所有的协议在OT混合模型中都是UC安全的，并且可以推广到具有任意数量恶意方的多方计算。
OD-Stega: LLM-Based Relatively Secure Steganography via Optimized Distributions
Department of Electrical and Computer Engineering, Texas A&M University（电气与计算机工程系，德克萨斯A&M大学）；Department of Computer Scicence and Engineering, Texas A&M University（计算机科学与工程系，德克萨斯A&M大学）
