LR-FEAD: leakage-tolerating and attribute-hiding functional encryption mechanism with delegation in affine subspaces

In large-scale networks, such as cloud computing and Internet of Things, functional encryption mechanism provides a flexible and powerful cryptographic primitive in constructing the secure transmission and communication protocols. However, as the side-channel attacks in open environments, the attacker can gain partial sensitive information from the pre-defined system by virtue of the time, power analysis, cold-boot attacks, etc. In this work, we design a leakage-resilient functional encryption scheme, which tolerates amount of bounded master-key leakage and user private-key leakage. In our scheme, encryption policies are specified as point vectors and decryption roles are defined as affine subspaces. Role delegation is implemented by specifying the affine transformation over subspaces. Our scheme achieves payload hiding and attribute hiding in the sense that the attacker is able to specify any efficiently computable leakage functions and learns the function outputs taking the master/private keys as inputs. Also, our scheme can tolerate the continual leakage for master key and private key, since we can periodically update the master key and the private key to generate a new and re-randomized key with the same distribution to the previous keys. We construct the scheme in composite-order bilinear groups and prove the security with dual system encryption methodology. We also analyze and discuss the performance of allowable leakage bound, leakage ratio and possible leakage probability. Our scheme has flexible applications in secure data communication and authorization delegation in open cloud computing systems.     

Overview about attacks on smart cards

When compared with data carriers such as cards with magnetic stripes or diskettes, the potential for protecting and securing data is one of the main advantages of cards with electronic chips (smart cards). Consequently, the chip hardware must be designed in an optimum fashion to meet this purpose; this includes the corresponding cryptographic procedures for securing the secret data. However, security is not only dependent on the specialised hardware of the microcontroller or on the cryptographic algorithms implemented in the operating system software. The security of applications for smart cards and the design principles applied by the developers to meet these security needs are of fundamental importance. The essential property of a smart card is its ability to offer a secure environment for data and programs. This article examines the range of possible attacks against smart cards, and the measures that can be used to protect against these attacks.     

基于云桌面实现网络安全隔离的应用

网络安全隔离技术是保护企业内部信息安全的重要手段,一般通过传统网络设备,如防火墙、网闸等实现隔离,但安全规则相对固化,无法较好满足灵活多变的业务需求。对实际外联需求进行分析,利用云桌面技术,结合合理的网络规划,设计并实现一种能够普遍推广的网络安全隔离应用方式。通过灵活运用更多安全手段,在确保网络安全隔离的基础上,进一步提升内外网使用体验。     

Detecting attacks on networks

As Internet based and intranet based network systems have evolved, they have become invaluable tools that businesses can use to share information and conduct business with online partners. However, hackers have also learned to use these systems to access private networks and their resources. Studies have shown that many organizations have suffered external and internal network intrusions. Internet systems are subject to various types of attacks. Traditional network security products, such as firewalls, can be penetrated from outside and can also leave organizations vulnerable to internal attacks. Generally, victims do not find out that their networks have been attacked until they examine system logs the next day, after the damage has been done. Network intrusion detection systems solve this problem by detecting external and internal security breaches as they happen and immediately notifying security personnel and network administrators by e mail or pager. Intrusion detection systems use several types of algorithms to detect possible security breaches, including algorithms for statistical anomaly detection, rule based anomaly detection, and a hybrid of the two     

入侵检测与防火墙的联动平台研究

分析了入侵检测系统与防火墙技术的各自优势,认为实现防火墙的数据过滤与入侵检测的实时监控间的有效互补是非常重要的。通过分析联动系统的理论知识,提出防火墙与入侵检测系统间的安全联动模型,实现两者之间的协同工作。这样无论是来自内网还是外网的攻击,都可以识别并自动响应。     

Access control and session management in the HTTP environment

As the only ubiquitous public data network, the Internet offers business partners a communications channel that previously existed only in unique situations with private, special-purpose networks. Well-publicized security risks, however, have limited the deployment of business-to-business extranets, which typically use the Internet's public data network infrastructure. These risks extend behind firewalls to intranets, where any user gaining entry to a facility is often implicitly authenticated to access unprotected services by simply plugging a portable computer into an unused network port. The author describes an approach that uses role-based access controls (RBACs) and Web session management to protect against network security breaches in the HTTP environment. The RBAC and session management services augment network-level security, such as firewalls, inherent in the deployment of any Web based system with untrusted interfaces. The RBACs are implemented through the Internet Engineering Task Force's Lightweight Directory Access Protocol (LDAP). Session management is implemented through cryptographically secured, cookie-based ticket mechanisms     

一种针对分组密码S盒的组合侧信道攻击方法*

近年来随着半导体工艺的飞速发展和信息安全的重要性不断增强,越来越多的硬件嵌入了密码算法以保证数据安全性。针对嵌入了FPGA密码芯片的设备在运行算法时泄漏的侧信道信息进行了研究,提出一种改进分组密码S盒的组合侧信道攻击方案,该方案由差分功耗攻击、模板攻击、和毛刺攻击构成。通过传统的差分功耗攻击确定S盒运行的时间区间,然后针对目标S盒的输入输出利用一个时钟周期内逻辑门毛刺个数与部分功耗线性相关的方法,采用线性模型匹配算法恢复密钥并减少了基于多元高斯模型匹配的计算量,为今后提高侧信道攻击的效率提供依据。     

防火墙与入侵检测系统联动架构的研究

随着网络上各种恶意攻击不断增多,加强网络防护措施、保护个人信息资源的安全是非常必要的,本文就对入侵检测系统及防火墙在网络防护上的优缺点进行分析,提出一种防火墙与入侵检测系统联动架构的实施方案,并对该方案的防护性能进行简单的分析。     

Cryptanalytic attacks on cyber-physical systems

Cryptography finds its application in various objects used in our everyday life. GSM communication, credit cards, tickets for public transport or RFID tags employ cryptographic features either to protect privacy or to ensure trustworthy authentication. However, many such objects are vulnerable to certain cryptanalytic attacks. In this review we discuss how FPGA-based cryptanalytic hardware may compromise GSM communication, or how standard laboratory equipment may be used for breaking Smart Card security. This review summarizes keynote speech that was given at 5th Mediterranean Conference on Embedded Computing (MECO’2016).     

一种混合云环境下基于Merkle哈希树的数据安全去重方案

重复数据删除技术是云存储系统中一种高效的数据压缩和存储优化技术,能够通过检测和消除冗余数据来减少存储空间、降低传输带宽消耗。针对现有的云存储系统中数据安全去重方案所采用的收敛加密算法容易遭受暴力攻击和密文计算时间开销过大等问题,提出了一种混合云环境下基于Merkle哈希树的数据安全去重方案MTHDedup。该方案通过引入权限等级函数和去重系数来计算去重标签,高效地实现了支持访问控制的数据安全去重系统;同时通过执行额外的加密算法,在文件级和数据块级的数据去重过程中构造Merkle哈希树来生成加密密钥,保证了生成的密文变得不可预测。安全性分析表明,该方案能够有效地抵制内部和外部攻击者发起的暴力攻击,从而提高数据的安全性。仿真实验结果表明,MTHDedup方案能有效地降低密文生成的计算开销,减少密钥的存储空间,而且随着权限集数目的增加,性能优势将更加明显。     

New Models and Methods for Estimating the Cryptographic Strength of Information Security Systems

A new approach to estimating information security of modern information and communication systems is proposed on the basis of the general theory of optimal algorithms. The relation between the quality of information and cryptographic strength of cryptographic and steganographic systems is shown. The choice of the radius of information as the cryptographic work factor is substantiated for various information security systems.     

基于国密算法和PUF的企业用户身份认证系统

针对当前企业信息系统登录方法安全性和可扩展性的不足,设计一种基于国密算法和PUF（物理不可克隆函数）的企业用户身份认证系统。该系统借鉴FIDO U2F（线上快速第二因子身份认证）认证框架,以身份识别令牌作为认证第二因子,使用国产加密算法实现安全性的自主可控,同时在身份令牌中集成了PUF和真随机数发生器,以达到提升安全性和可扩展性的目的。安全性分析表明,该系统的安全性显著高于现有技术实现。实验测试结果表明,该系统运行开销较低,稳定可靠,能够方便、快捷地部署在企业信息系统中。     

Stochastic stability analysis of networked control systems with random cryptographic protection under random zero-measurement attacks

Security issues in networked control systems (NCSs) have received increasing attention in recent years. However, security protection often requires extra energy consumption, computational overhead, and time delays, which could adversely affect the real-time and energy-limited system. In this paper, random cryptographic protection is implemented. It is less expensive with respect to computational overhead, time, and energy consumption, compared with persistent cryptographic protection. Under the consideration of weak attackers who have little system knowledge, ungenerous attacking capability and the desire for stealthiness and random zero-measurement attacks are introduced as the malicious modification of measurements into zero signals. NCS is modeled as a stochastic system with two correlated Bernoulli distributed stochastic variables for implementation of random cryptographic protection and occurrence of random zero-measurement attacks; the stochastic stability can be analyzed using a linear matrix inequality (LMI) approach. The proposed stochastic stability analysis can help determine the proper probability of running random cryptographic protection against random zero-measurement attacks with a certain probability. Finally, a simulation example is presented based on a vertical take-off and landing (VTOL) system. The results show the effectiveness, robustness, and application of the proposed method, and are helpful in choosing the proper protection mechanism taking into account the time delay and in determining the system sampling period to increase the resistance against such attacks.     

An event-based platform for collaborative threats detection and monitoring

Organizations must protect their information systems from a variety of threats. Usually they employ isolated defenses such as firewalls, intrusion detection and fraud monitoring systems, without cooperating with the external world. Organizations belonging to the same markets (e.g., financial organizations, telco providers) typically suffer from the same cyber crimes. Sharing and correlating information could help them in early detecting those crimes and mitigating the damages.The paper discusses the Semantic Room (SR) abstraction which enables the development of collaborative event-based platforms, on the top of Internet, where data from different information systems are shared, in a controlled manner, and correlated to detect and timely react to coordinated Internet-based security threats (e.g., port scans, botnets) and frauds. In order to show the flexibility of the abstraction, the paper proposes the design, implementation and validation of two SRs: an SR that detects inter-domain port scan attacks and an SR that enables an online fraud monitoring over the Italian territory. In both cases, the SRs use real data traces for demonstrating the effectiveness of the proposed approach. In the first SR, high detection accuracy and small detection delays are achieved whereas in the second, new fraud evidence and investigation instruments are provided to law enforcement agencies.     

On the security of MQ cryptographic systems for constructing secure Internet of medical things

The Internet of Medical Things (IoMTs) are the group of medical devices connected to Internet, to perform the processes and services that support healthcare. The amount of data handled by medical devices grows exponentially, which means higher exposure of personal sensitive data. RSA, ECC and, other related public key cryptographic systems with countermeasures of power analysis and fault analysis, e.g., random masking, are often adapted by medical devices for guaranteing security and privacy. However, Shor algorithm has proven that they are not secure to quantum computer attacks. Fortunately, there exists a few quantum-resistant public key cryptographic schemes, e.g., Rainbow. To ensure end-to-end service delivery in the IoMTs under quantum attacks, there is a critical need for research into new designs and evaluation for the hardware security of new quantum-resistance cryptographic systems, e.g., rainbow, to make the medical devices more secure and reliable. Therefore, we present a physical analysis model of Rainbow by combining fault analysis and differential power analysis. The proposed model is implemented on cloud computing platform. Based on the experimental results, we successfully recover all the secret keys of Rainbow signature, which shows the importance of protecting multivariate signature with countermeasures on medical devices.     

Study on two privacy-oriented protocols for information communication systems

In these days, the privacy of a user in information communication system is more important than ever before. Especially, the property is important for mobile communication systems due to the mobility of underlying mobile devices. Until now, many cryptographic tools have been proposed for achieving users’ privacy. In this paper, we review two privacy-oriented cryptographic protocols, and show their security holes. We also provide some countermeasure to fix the weaknesses. First, we discuss the security of the user identification scheme proposed by Hsu and Chuang which permits a user to anonymously log into a system and establish a secret key shared with the system. We show that the Hsu-Chuang scheme is not secure against known session key attacks, and then we provide a countermeasure which can be used for enhancing the security the Hsu-Chuang scheme. Secondly, we review a deniable authentication proposed by Harn and Ren which protects the privacy of a message sender. Then we show that the protocol has a potential incompleteness and two weaknesses.     

工业控制系统网络入侵检测方法综述

随着工业控制系统(industrial control systems,ICS)的网络化,其原有的封闭性被打破, 各种病毒、木马等随着正常的信息流进入ICS,已严重威胁ICS的安全性,如何做好ICS安全防护已迫在眉睫.入侵检测方法作为一种主动的信息安全防护技术可以有效弥补防火墙等传统安全防护技术的不足,被认为是ICS的第二道安全防线,可以实现对ICS外部和内部入侵的实时检测.当前工控系统入侵检测的研究非常活跃,来自计算机、自动化以及通信等不同领域的研究人员从不同角度提出一系列ICS入侵检测方法,已成为ICS安全领域一个热点研究方向.鉴于此,综述了ICS入侵检测的研究现状、存在的问题以及有待进一步解决的问题.     

基于硬件的防火墙实现技术

目前占主流的防火墙都是基于软件来实现的,通过各种技术组合可以达到比较高的安全级别。但是软件防火墙始终存在着一些避免的安全性问题,而基于硬件实现的防火墙则可以比较好地解决这些问题。该文将详细介绍一种基于硬件的防火墙技术－Ｈａｒｄｗａｌｌ。     

A novel three-tiered visualization approach for firewall rule validation

Firewall is one of the most critical elements of the current Internet, which can protect the entire network against attacks and threats. While configuring the firewalls, rule configuration has to conform to, or say be consistent with, the demands of the network security policies such that the network security would not be flawed. For the security consistency, firewall rule editing, ordering, and distribution must be done very carefully on each of the cooperative firewalls, especially in a large-scale and multifirewall-equipped network. Nevertheless, a network operator is prone to incorrectly configure the firewalls because there are typically thousands or hundreds of filtering/admission rules (i.e., rules in the Access Control List file, or ACL for short), which could be set up in a firewall; not mentioning these rules among firewalls affect mutually and can make the matter worse. Under this situation, the network operator would hardly know his/her misconfiguration until the network functions beyond the expectation. For this reason, our work is to build a visualized validation system for facilitating the check of security consistency between the rule configuration of firewalls and the demands of network security policies. To do so, the developed validation system utilizes a three-tiered visualization hierarchy along with different compound viewpoints to provide users with a complete picture of firewalls and relationships among them for error debugging and anomaly removal. In addition, in this paper, we also enumerate the source of security inconsistency while setting ACLs and make use of it as a basis of the design of our visualization model. Currently, part of the firewall configuration of our campus network has been used as our system's input to demonstrate our system's implementation.     

A session key caching and prefetching scheme for secure communication in cluster systems

With the widespread use of cluster systems and ever increasing threat to computer security, it becomes more necessary to design and build secure cluster systems. Most cluster systems rely on security products like firewalls for their security, but they cannot guarantee security of intra-cluster communications, which can be a weak spot that hackers exploit for further security attacks. A recent study by Lee and Kim (2007) [22] proposed a security framework to protect intra-cluster communications by encrypting and authenticating all packets with fine-grained security where any two communicating processes dynamically generate and share a cryptographic key, called a session key. However, the fine-grained security scheme can incur serious performance degradation in large-scale cluster systems since it may take a long time to access session keys. To solve this problem, we propose to incorporate a session key cache inside a cluster interconnect card to speed up accesses to the session keys and build an analytical cluster traffic model to estimate the behavior of the cache in large-scale cluster systems. For further performance improvement, we propose a prefetching scheme speculating job scheduler’s decision without OS interventions. Simulation results indicate that the session key cache with the prefetching scheme decreases the network latency by 50% on average, compared to the configurations without the enhancements.