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SACM (Structured Assurance Case Metamodel) is a standard for assurance case specification and exchange. It consists of an argumentation metamodel and an evidence metamodel for justifying that a system satisfies certain requirements. For assurance of safety-critical systems, SACM can be used to manage safety evidence and to specify safety cases. The standard is a promising initiative towards harmonizing and improving system assurance practices, but its suitability for safety evidence management needs to be further studied. To this end, this paper studies how SACM 1.1 supports this activity according to requirements from industry and from prior work. We have analysed the notion of evidence in SACM, its evidence lifecycle, the classes and associations of the evidence metamodel, and the link of this metamodel with the argumentation one. As a result, we have identified several improvement opportunities and extension possibilities in SACM. The notions of evidence and evidence assertion should be clarified, the overlaps between metamodel elements should be reduced, and a wider support to the lifecycle of the artefacts used as safety evidence could be provided. Addressing these aspects will allow SACM to better fit safety evidence management needs and practices, especially beyond the scope of a safety case. The results and the conclusions drawn are especially valuable for practitioners interested in SACM adoption and vendors interested in developing tool support for SACM-based safety evidence management. [ABSTRACT FROM AUTHOR]

Abstract: Password-based authentication is widely used for systems that control remote access to computer networks. In order to address some of the security and management problems that occur in traditional password authentication protocols, research in recent decades has focused on smart card based password authentication. In this paper, we show that the improved smart card authentication scheme proposed by Xu-Zhu-Feng is vulnerable to internal and impersonation attacks. We propose an improvement of their solution, present a new efficient strong smart card authentication protocol, and demonstrate that the new protocol satisfies the requirements of strong smart card authentication and is more efficient. [Copyright &y& Elsevier]

Abstract: Web services are among the applications involving closely the customers'' private informations. In order to take into account the privacy concerns of the individuals, organizations provide privacy policies as promises describing how they will handle personal data of the individual. However, privacy policies do not convince potential individuals to disclose their personal data, do not guarantee the protection of personal information, and do not provide how to tackle the evolution of the policies. In this paper, we introduce a framework based on an agreement as a solution to these problems. It contains a privacy model defined in the policy level of the agreement. We provide upon it a reasoning mechanism for the evolution. The framework supports in the negotiation level of the agreement a lifecycle management which is an important deal of a dynamic environment that characterizes Web services. A negotiation protocol is proposed to enable ongoing privacy negotiation to be translated into a new privacy agreement. [Copyright &y& Elsevier]

Abstract: The Extensible Authentication Protocol (EAP) has been standardized within the Internet Engineering Task Force (IETF) in order to provide flexible mechanisms for authentication and key management for network access control. However, some deficiencies have been revealed and recognized as a major obstacle to achieving secure and seamless handover in mobile scenarios. HOKEY (Handover Keying) Working Group in IETF is standardizing low-latency EAP re-authentication and key distribution protocols to address these deficiencies. This paper provides a critical analysis of the on-going work. [Copyright &y& Elsevier]

Abstract: This paper considers the issue on authenticated group key agreement protocol among n users broadcasting communication over an insecure public network. Many authenticated group Diffie-Hellman key agreement protocols have been proposed to meet the challenges. However, existing protocols are either limited by the use of public key infrastructure or by their scalability, requiring O(n) rounds. To overcome these disadvantages, we propose an efficient password-based group key agreement protocol resistant to the dictionary attacks by adding password-authentication services to a non-authenticated multi-party key agreement protocol proposed by Horng. The proposed protocol is very efficient since it only requires constant rounds to agree upon a session key, and each user broadcasts a constant number of messages and only requires four exponentiations. Under the Decisional Diffie-Hellman assumption, we will show the proposed protocol is provably secure in both the ideal-cipher model and the random-oracle model. [Copyright &y& Elsevier]

Abstract: Robust continuity should be paid much more attention in sensor network key management protocols, especially in privacy-vital environment. However, to our best of knowledge, few papers on key management have addressed the robust continuity in sensor networks. Therefore, in this paper, we present a new key management protocol with robust continuity for sensor networks. The purpose is to minimize the key management redesign effort as well as to make the node flexible and adaptable to many different applications. Compared to existing key management protocols, our proposed protocol has the following merits: First, our protocol addresses the continuity between the pairwise key and group key, it can establish the pairwise key and group key with the same pre-distributed secrets. Second, our protocol can deal with the continuity of the pairwise key and the group key themselves; it can update both of them to support the changes in the size of the network. [Copyright &y& Elsevier]

Abstract: The study deals with the analysis of latency introduced by the media access control algorithm of LonTalk protocol registered as ANSI/CEA-709.1 standard and used in LonWorks control networking technology. The LonTalk protocol provides multicast communication which is a distinctive feature among control network protocols. The predictive p-persistent CSMA protocol built in the MAC sublayer uses the memoryless backoff, additive increase/additive decrease contention window adjustments, provides collision avoidance and optional collision detection. The behavior of the LonTalk MAC protocol, unlike of the other CSMA schemes, is forced not only by the traffic rate but also by the structure of the workload transmitted through the channel. Therefore, the predictive p-persistent CSMA performance depends on the load scenario defined as the specification of the input traffic generated to the network. In the study, a unified method of load scenario definition integrating various addressing and message service types, is used. The contribution of the paper is the adaptation of the analytical approach based on Markov chains to the evaluation of mean access delay of LonTalk protocol for any load scenario. [Copyright &y& Elsevier]

Abstract: Free roaming mobile agent [D. Xu, L. Harn, M. Narasimhan, J. Luo. “An Improved Free-Roaming Mobile Agent Security Protocol against Colluded Truncation Attacks.” In Proceedings of the 30th Annual international Computer Software and Applications Conference(COMPSAC,06), Volume 2, Page(s):309–314,Chigago, Sept. 2006, IEEE Computer Society Press.; S. Venkatesan, C. Chellappan, “Protecting free roaming mobile agent against multiple colluded truncation attacks”, In proceedings of the 3rd International conference on Mobile Multimedia Communication (Mobimedia''07), page(s): 293–297, August 2007.] is to collect information from more number of remote host using the shortest route. The routing table available in the router is not applicable for the free roaming mobile agent to roam around the network, so each and every server must have the routing information. This paper proposes a model to generate the routing table for the free roaming mobile agent to roam around the network by calculating the link cost between the nodes. Link cost between the servers is measured by the energy consumed to reach the destination. Link cost is measured by the transmission of agent instead of sending the message because here the route is calculated for agent roaming. The cost for transferring the message and the agent differs because of the migration and transfer. In agent transmission, the whole thing will be migrated to the remote host. But in the message transmission, the particular message is transmitted. Routing table in the destination will be generated automatically by the mobile agent while it visits the destination host and the routing table of the source host will be generated after the agent returns to its home (source host). [Copyright &y& Elsevier]

Abstract: In the last years the amount of information being transmitted through communication networks has increased, and this has lead to an increased use of security protocols. The implementations of security protocols do not accurately follow the standards and this causes many malfunctions and security flaws. In this paper we will analyze the different approaches followed by the scientific community to evaluate security protocols'' implementations, and will also analyze the special characteristics of security protocols, in order to deduce which are the key points for such an evaluation, how they can be evaluated and also if existing evaluation techniques can be used. [Copyright &y& Elsevier]

Abstract: In many network applications, including distant learning, audio webcasting, video streaming, and online gaming, often a source has to send data to many receivers. IP multicasts and application-layer multicasts provide efficient and scalable one-to-many or many-to-many communications. A common secret key, the group key, shared by multiple users can be used to secure the information transmitted in the multicast communication channel. In this paper, a new group key management protocol is proposed to reduce the communication and computation overhead of group key rekeying caused by membership changes. With shared key derivation, new keys derivable by members themselves do not have to be encrypted or delivered by the server, and the performance of synchronous and asynchronous rekeying operations, including single join, single leave, and batch update, is thus improved. The proposed protocol is shown to be secure and immune to collusion attacks, and it outperforms the other comparable protocols from our analysis and simulation. The protocol is particularly efficient with binary key trees and asynchronous rekeying, and it can be tuned to meet different rekeying delay or key size requirements. [Copyright &y& Elsevier]

Abstract: This paper proposes a new approach, named Card-Aided Firewall (CAF) that combines the simplified firewall and the state-oriented smart card technologies to construct a controllable and accountable Internet access framework. The idea suggests that a client computer, protected by a light-weight firewall, could establish diversified authenticated communication channels, controlled and accounted by “legal” states of the smart card. The program of a smart card is state-oriented or a state machine, which defines a chain of events involving various state transitions. The “legal” states of a smart card program are defined to be legal to communicate with surfing targets. A predefined Access Control List (ACL), stored in the same card, is necessary. An ACL is a sequential list of permit or deny statements that apply to addresses or upper-layer protocols. The proposed firewall decides acceptance or rejection messages by matching the current state of the card program and the ACL. In addition, a complete surfing account for tracing back is recorded. It is a by-product of the smart card authentication. The proposed Card-Aided Firewall framework is implemented to demonstrate its effectiveness. The implementation is done at the driver level. It keeps up with the high line speed. The driver takes 39K bytes and works well with other firewalls. The average packet processing time of the CAF driver is 31.74 μs. On the premise of secure authentication within the smart card, the Card-Aided Firewall would facilitate various rapidly growing applications in campus cards, family cards, and employee cards, etc. that require accurate controllability and accountability in the surfing boundary. [Copyright &y& Elsevier]

Abstract: The rights of an Internet user acting anonymously conflicts with the rights of a Server victim identifying the malicious user. The ERPINA protocol, introduced in this paper, allows an honest user communicating anonymously with a Server through a PET, while the identity of a dishonest user is revealed. Prior research failed to distinguish objectively between an honest user and an attacker; and a reliable and objective distinguishing technique is lacking. The ERPINA protocol addresses the reliability issue efficiently by defining from the beginning of the communication what is considered as malicious and what is not. [Copyright &y& Elsevier]

Abstract: Recently, two e-mail protocols were proposed claiming to provide perfect secrecy. These protocols use authentication and (Diffie-Hellman) key-exchange techniques, and as such, other standard security criteria besides perfect forward secrecy include key-replay resilience, known-key security, key freshness and unknown key-share resilience are expected too. In this paper, we show that the two protocols cannot resist replay attacks, and further that the first falls to unknown key-share attacks while the second fails to provide perfect forward secrecy, contrary to the designers'' claims. Although the two protocols were intended by the designers to be more secure variants compared to the common e-mail protocol, our results show that being newer does not necessarily mean being more secure. [Copyright &y& Elsevier]

In this paper we point out potential weaknesses of AuthA protocols which are in the process of being standardized by IEEE; IEEE P1363-Password-based authentication and key agreement protocols. More precisely, we present chosen protocol attacks on AuthA password-authenticated key agreement protocols. We make suggestions for improvement. [Copyright &y& Elsevier]

Abstract: Secure key issuing in identity-based cryptosystems is a challenging task due to the inherent drawback of key escrow. Several protocols have been proposed for key issuing which do not require secure channel and eliminate key escrow problem. However, the existing secure and efficient protocol requires all the participating authorities to be mandatorily available for constructing the user''s private key. We present a secure and robust protocol for key issuing in identity-based cryptosystems by using the concept of threshold cryptosystems, which avoids the practical limitation. [Copyright &y& Elsevier]

Abstract: As low-cost Radio Frequency Identification (RFID) will become pervasive in our daily lives, RFID systems may create new threats to the security and privacy of individuals and organizations. However, the previous works on designing security protocols for RFID either do not conform to the EPC Class 1 Generation 2 standards or suffer from security flaws. This paper will point out the weaknesses of two EPC Class 1 GEN-2-conformed security protocols, and then proposes our new protocol, which raises the security level and conforms to the EPC Class 1 GEN-2 standards. [Copyright &y& Elsevier]

This study addresses the specifiable verifier characteristics of the group-oriented threshold signature in a group-oriented cryptosystem. Based on these characteristics, the group of signers has a limited authority to specify the group of verifiers. Furthermore, the elliptic curve cryptosystem is integrated into the proposed scheme to increase the efficiency above that of other algorithms. [Copyright &y& Elsevier]

Recently, there are several articles proposed for the so-called SAS password authentication scheme with lower storage, processing, and transmission overheads. For benefiting from these advantages, there are a series of researches on the SAS-like schemes. However, as knowledge of cryptanalysis has involved, a series of modification have been made. Unfortunately, those enhancements have still security flaws. In this paper, a security issue is found in the latest modification and removed to form a new one. The proposed schemes not only keep the original advantages but also highlight a feature, mutual authentication between a user and a remote server, found in many authentication protocols but not found in the SAS-like schemes. [Copyright &y& Elsevier]

Tseng-Jan modified a non-interactive public key distribution system and also proposed several applications based on the Maurer–Yacobi scheme. In their scheme, a user can prove his identity to another user without revealing his secret key. They use a challenge-response-type interactive protocol to achieve their objective. However, in wireless environment, waiting for a corresponding response from the other is time-wasting and consumes the battery of the mobile device. The ability of computing and the capacity of the battery of a mobile device are limited. Therefore, we propose an efficient scheme based on ID-based cryptosystem that is more suitable to be applied in the mobile environment. [Copyright &y& Elsevier]

The passwords people can remember are usually simple or meaningful. In three-party key exchange protocols with password authentication, clients are allowed to share an easy-to-remember password with a trusted server such that two clients can communicate with each other through a common secret key without the existence of redundant keys. Such protocols are quite suitable for application when light-weight clients need secure communications. Steiner, Tsudik, and Waidner proposed a three-party protocol based on the encrypted key exchange (EKE) protocols in 1995; however, the proposed protocol suffered from off-line and undetectable on-line guessing attacks. In 2000, Lin, Sun, and Hwang proposed a secure three-party protocol with server''s public keys. Because certificates are needed to verify the server''s public keys to avoid impersonation attacks, this protocol is not practical for some environments. In 2001, Lin, Sun, Steiner and Hwang proposed a brand-new three-party protocol without servers'' public keys. Nevertheless, more rounds are needed by using this protocol. In this paper, we propose a secure three-party EKE protocol with round efficiency. [Copyright &y& Elsevier]

Abstract: The APSSNMP network management protocol was proposed as a secure alternative to the Simple Network Management Protocol (SNMP) used in the TCP/IP suite. The designers claimed that it resists meet-in-the-middle (MITM) attacks. In this paper, we present an advanced MITM attack on the APSSNMP and hence show that it fails to achieve its design objective of providing better security against MITM attacks. Since the APSSNMP has been presented in several journals, and IEEE and IASTED conferences, our result is important to highlight to network implementers and users of distributed systems that the APSSNMP is not secure for practical deployment. [Copyright &y& Elsevier]