Catálogo de publicaciones - libros

The security manager in Java 2 is a runtime access control mechanism. Whenever an access permission to critical resources is requested, the security manager inspects a call stack to examine whether the program has appropriate access permissions or not. This run-time permission check called enforces access-control policies that associate access rights with the class that initiates the access. In this paper, we develop a visualization tool which helps programmers enforce security policy effectively into programs. It is based on the static permission check analysis which approximates permission checks statically which must succeed or fail at each method. Using the visualization system, programmers can modify programs and policy files if necessary, as they examine how permission checks and their stack inspection are performed. This process can be repeated until the security policy is enforced correctly.

As a remarkable realization of the simple idea ”Physical Separation”, the Lock-Keeper technology has been proven to be a practical approach to provide high-level security for a sensitive internal network by completely separating it with the less secure external network. The data exchange between the two separated networks is accomplished by the Lock-Keeper Secure Data Exchange software which is occupied by three PC-based Lock-Keeper components: INNER, OUTER and GATE. The SDE’s application modules on INNER and OUTER provide specific network services to the external world through normal network connections and organize the network traffic into Lock-Keeper-mode units which can be transferred through the Lock-Keeper by its SDE’s basic data exchange modules on INNER, OUTER and GATE. There is an extra data scanning module located on GATE to check the passing data contents. In this paper, a new implementation of the SDE software will be proposed based on the Virtual Machine technology. Application modules on INNER and OUTER are respectively replaced by some Virtual Machines. According to different requirements of corresponding applications, different configurations and resource assignments can be employed by these Virtual Machines. Such special-purpose Virtual Machines and their underlying host can be isolated from one another by the natural property of the Virtual Machine technology so that both the host and each single application can be easily restored in the case of destruction. In addition, a content scanning VM will be built on GATE to support offline scanning, configuration, updating and other useful extension.

In this paper we investigate implementations of ARIA on an 8-bit smartcard. Our investigation focuses on the resistance against different types of differential power analysis (DPA) attacks. We show that an unprotected implementation of ARIA allows to deduce the secret key with a low number of measurements. In order to thwart these simple DPA attacks, we mask and randomize the ARIA implementation on the smartcard. It turns out that due to the structure of ARIA, a masked implementation requires significantly more resources than an unprotected implementation. However, the masked and randomized implementation provides a high resistance against power analysis attacks.

One of the most promising applications of active RFID tags is , which is an electronic device to guarantee the authenticity and integrity of freight containers and also provides physical protection like a lock. There are already many commercial electronic seal products and ongoing standardization activities such as ISO-18185 drafts. While electronic seals can provide freight containers with a high level of tamper resistance, the security problem of electronic seal itself should be solved, and a feasible solution would be to use symmetric key cryptography based primitives such as block ciphers and message authentication codes (MACs). This kind of approach has already been used in many security-related standards and it requires the implementation of pseudorandom functions (PRFs) for key derivation and authentication.

In this paper, we consider secure and efficient implementation of PRFs on electronic seals and interrogators. We implement block cipher based PRFs and hash based PRFs and compare them from the viewpoint of efficiency. Since practical PRFs can be directly implemented using MACs, we consider implementation of various message authentication schemes; HMAC-MD5, HMAC-SHA1, AES-CBC-MAC, AES-CMAC and AES-XCBC-MAC. For interrogators, we design FPGA modules for these MAC algorithms since an interrogator has to guarantee high throughput to communicate with many electronic seals simultaneously. According to our analysis, AES based MACs consume smaller areas and their throughputs are significantly higher than hash based ones. For electronic seals, we implement MAC algorithms as a form of software module (C and assembly codes) over a small-scale microcontroller. Our experimental results show that AES based modules show much better performance, which coincide with the results in hardware implementation. Finally, we improve the above implementations further, where we concentrate on the optimization of AES based MACs. We use several well-known techniques such as use of block RAMs in FPGA, and loop unrolling and register reallocation in assembly code.

Due to the rapid advancement of cryptographic techniques, the smart card has recently become a popular device capable of storing and computing essential information with such properties as tamper-resistance and guessing-lock. However, most electronic transactions are in fact performed in the multi-server environment, which unfortunately means conventional authentication schemes cannot satisfy both of the basic requirements: security and efficiency. To make a difference, Juang proposed scheme in February 2004. Nevertheless, there still exist two drawbacks in Juang’s scheme: (1) they need this registration center to distribute the shared key when the user logins the server for services; (2) the authentication scheme lacks round efficiency. In this paper, we proposed an efficient and secure multi-server authenticated key agreement scheme, where the user only needs to register once and can be authenticated without any registration center. Furthermore, the proposed scheme can be employed for the use of mobile networks because of its low computation load and round efficiency.

A mobile ad hoc network (MANET) is a collection of wireless mobile nodes forming a temporary network without any established infrastructure. MANETs are generally more vulnerable to security threats than fixed wired network due to its inherent characteristics such as absence of infrastructure, dynamically changing topologies. The selection of IDS operating node is one of critical issues because of energy limited feature of a MANET. In this paper, we propose a cost-effective IDS operating node selection scheme by solving cost minimization problem in a MANET. The results illustrate that our proposed algorithm can reduce the total cost while maintaining appropriate security level in a MANET.

In this paper, we design and propose an efficient and secure authentication method for global and local binding update in HMIPv6 as well as for fast handover in HMIPv6. Also, we introduce a group key management scheme among MAP and ARs in a MAP domain and use a ticket to authenticate local binding update message. We analyze the security and for the comparison with other schemes, analyze performance using the random-walk mobility model and present numerical results based on it.

Recently, the number of troubles about the user authentication for network services by phishing or spyware has been increasing. Utilizing hardware tokens such as IC cards, OTP cards, USB keys, or mobile phones are paid attention for making user authentications secure. However, most of the existing methods tend to take a lot of effort and costs for introducing hardware tokens. In addition, although the some methods are easy to be introduced, there are the problems about eavesdropping of the authentication information by malicious-ware such as key loggers. In this paper, we propose a user authentication method which does not need input and send the authentication information between a user terminal and a network service provider via the Internet, instead a one-time token that is issued by the provider and displayed as a matrix code on the user terminal, and the user reads the information with a matrix code reader on the user’s mobile phone, and convert and transmit it to the provider via a comparatively trusted mobile phone carrier’s network. The prototype system is implemented, and the user experiments which compare fix password type, two-factor one-time password type, and proposed type, were performed. As a result of a questionnaire about the usability, it was verified that the proposed method could impress users with comparatively high security and usability.

Version 2.0 of the Open Mobile Alliance’s Digital Rights Management Specification provides for protected content to be shared amongst a collection of devices in a . Domains are created and managed directly by the rights issuer that issues rights to the domain. In this paper, we propose to devolve the management of domains to a domain manager known as that acts as a broker between the devices in an authorised domain and any content providers from which content for the domain can be sourced. We describe and compare three different modes in which Heimdall might operate.

In this paper, we discuss collusion-secure traceability codes for digital fingerprinting which is a technique for copyright protection of digital contents. We first state a generalization of conventional collusion attacks where illicit users of a digital content collude to create an illegal digital content. Then we propose a collusion-secure traceability code which can detect at least one colluder against it. We show the rate and properties of the proposed traceability code.