Traditionally, industrial control systems operate in isolated networks with proprietary solutions. As smart factories and digital twins have become inevitable with AI advancement, the rapid adoption of Industrial Internet of Things (IIoT) devices has significantly increased cybersecurity risks. More precisely, the complexity of industrial environments, which includes production processes and device roles, creates substantial challenges for secure deployment. The authors introduce a bottom-up, industrial role-oriented verification framework (IROVF) for manufacturing line deployment. IROVF incorporates SCADA's MTU and RTU components, which are mapped to distinct device roles. This provides authentication and least-privilege principles that are tailored to factory environments. The proposed framework designs an alarm strategy, which can be helpful to detect and report potential operational disruptions during runtime, thus minimizing impact on system availability. Experimental results demonstrate the superior security coverage of the proposed framework compared to existing research, while a comprehensive application scenario validates its practical applicability. The scalable security parameters of IROVF allow organizations to select appropriate security levels based on their specific requirements. IROVF provides an effective security solution for modern industrial control systems during deployment phases.

Halftoning schemes are developed for reserving the quality after transforming continuous tone images to binary images under human vision, and are widely used in printing and outputting. Modern halftoning schemes focus on transforming forward and backward the two kinds of images, but basic operations for halftone images like rescaling, blurring and sharpening are still insufficient. In this paper, a novel halftone image resampling scheme based on interpolation and error-diffusion is proposed. The proposed scheme can shrink and magnify halftone images to any desired scale and does not limit the source of the halftone images. To obtain the best performance, an evaluation tool is proposed to test various combinations of interpolation techniques and error-diffusion kernels. Due to the lack of evaluation research, the evaluation metric called light invariance is developed to evaluate the consistency before and after resampling. By the proposed scheme, resampling halftone images does not need transforming to and back from continuous-tone images anymore.

Secure multicast provides efficient delivery which includes an identical data from a source to multiple receivers. A common solution is to apply a symmetric key that is used to encrypt the transmitted data. However, the heavy cost of the rekeying process is the main problem in large and dynamic multicast groups. The tree-based architecture is widely used to reduce the rekeying cost in terms of storage, transmission and computation. However, it usually requires extra overhead to keep key tree balance which is in order to achieve logarithmic rekeying cost. In this paper, we shall propose a new RSA-like multicast key management scheme to solve the rekeying problem. Our protocol applies a star-based architecture to eliminate the rekeying processes and provide the good performance when the membership changes in a multicast group. Furthermore, we also provide an extended multicast scheme, in which we combine public-key and symmetric-key cryptosystems to enhance the performance of multicast encryption.

Recently, many researches have focused on a multi-tiered architecture for sensor networks. The advantages of such an architecture are better scalability, energy efficiency and security. Unfortunately, the homogeneous sensor networks lack these advantages. Thus, we use this multi-tiered architecture in this paper. Wireless sensor networks are usually deployed in hostile or dangerous environments, so the communications among nodes have to be encrypted. Furthermore, adversaries may capture or compromise nodes in the sensor networks. The keying material of the compromised nodes may be known by adversaries. Thus, the consequence of node capture attack has to be minimized. In this paper, we employ a polynomial to establish a pairwise key between any two nodes in a cluster. In addition, each sensor can also establish pairwise keys, in all probability, with its neighbors deployed in other clusters. The security analysis shows that our scheme provides better security, compared with the existing key establishment scheme.

We invented a progressive image transmission scheme that is used for transmitting Chinese calligraphy. The scheme employs the property of simple colors of calligraphy images to design a method of transmitting images phase by phase. Overall, our scheme can achieve the following two goals. One is compressing the image data to reduce the transmission time while the other is gaining less response time by using progressive image transmission. Furthermore, the recovered image still maintains the colors of the seals with high image quality.

Abstract A mobile agent is a technological promising product. It is an executive program that can migrate from host to host, performing tasks autonomously. However, in an open environment, the mobile agent has many potential threats. Security becomes a critical issue for the mobile agent. Recently, Volker and Mehradad have constructed a mobile agent structure and designed a key assignment strategy to prevent the sensitive data to from being accessed by an unauthorized host. However, their scheme requires a larger agent size and a higher computational cost. In this paper, we shall propose an efficient key assignment scheme to enhance the performance of Volker and Mehradad's scheme. Only few computations and a fixed and small storage are required in our proposed scheme. Furthermore, our scheme can achieve the dynamic key management efficiently. It can also be implemented simply and practically. Copyright © 2006 John Wiley & Sons, Ltd.

In a protection system, some mechanism is needed for determining the relationship between any two users so as to be used to help the decision making requests to change access attributes. In this paper, we propose a mechanism in the partially ordered user hierarchy, instead of the tree hierarchy discussed till now, by assigning each user an interpolating polynomial constructed from the user's own id number and his fathers'. In this way, any two users' relationship can be quickly determined from evaluating their associated polynomials. Moreover, whenever a new user is added into or deleted from the user hierarchy, none or only some relevant polynomial needs to be updated, different from allover the information needs to be reconstructed as shown in the previously proposed schemes.

A key assignment scheme whose security is based on solving discrete logarithms is proposed to work out a solution on the access control problem in an arbitrary partially ordered user hierarchy. Each user is assigned a secret key used to efficiently derive his successors' secret key and assigned an encryption key at the same time used to encrypt his information items or files only. Thus, any user can freely change his own encryption key for some security reasons without caring about those security classes with lower clearances to make their information items been reenciphered. And moreover, make a security class be added into or deleted from the hierarchy without changing any issued keys.

In a (t, n) threshold proxy signature scheme, the original signer delegates the power of signing messages to a designated proxy group of n members. Any t or more proxy signers of the group can cooperatively issue a proxy signature on behalf of the original signer, but (t - 1) or less proxy signers cannot. Previously, all of the proposed threshold proxy signature schemes have been based on the discrete logarithm problem and do not satisfy all proxy requirements. In this paper, we propose a practical, efficient, and secure (t, n) threshold proxy signature scheme based on the RSA cryptosystem. Our scheme satisfies all proxy requirements and uses only a simple Lagrange formula to share the proxy signature key. Furthermore, our scheme requires only 5 percent of the computational overhead and 8 percent of the communicational overhead required in Kim's scheme.

Conventional remote password authentication schemes allow a serviceable server to authenticate the legitimacy of a remote login user. However, these schemes are not used for multiserver architecture environments. We present a remote password authentication scheme for multiserver environments. The password authentication system is a pattern classification system based on an artificial neural network. In this scheme, the users only remember user identity and password numbers to log in to various servers. Users can freely choose their password. Furthermore, the system is not required to maintain a verification table and can withstand the replay attack.

The weaknesses of the simple authenticated key agreement (SAKA) protocol were shown by H. Sun (2000). These weaknesses include the following facts: (1) it cannot detect a masquerade, (2) it cannot withstand a dictionary attack, and (3) it cannot provide perfect forward secrecy. In this paper, we improve the SAKA algorithm to overcome these weaknesses. In addition, we show that the improved scheme is more simple and more secure than the original one.