152,761 research outputs found

    Group key establishment protocols: Pairing cryptography and verifiable secret sharing scheme

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    Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2013Includes bibliographical references (leaves: 97-103)Text in English; Abstract: Turkish and Englishx, 154 leavesThe aim of this study is to establish a common secret key over an open network for a group of user to be used then symmetrical secure communication between them. There are two methods of GKE protocol which are key agreement and key distribution. Key agreement is a mechanism whereby the parties jointly establish a common secret. As to key distribution, it is a mechanism whereby one of the parties creates or obtains a secret value and then securely distributes it to other parties. In this study, both methods is applied and analyzed in two different GKE protocols. Desirable properties of a GKE are security and efficiency. Security is attributed in terms of preventing attacks against passive and active adversary. Efficiency is quantified in terms of computation, communication and round complexity. When constructing a GKE, the challenge is to provide security and efficiency according to attributed and quantified terms. Two main cryptographic tools are selected in order to handle the defined challenge. One of them is bilinear pairing which is based on elliptic curve cryptography and another is verifiable secret sharing which is based on multiparty computation. In this thesis, constructions of these two GKE protocols are studied along with their communication models, security and efficiency analysis. Also, an implementation of four-user group size is developed utilizing PBC, GMP and OpenSSL Libraries for both two protocols

    Semi-quantum private comparison and its generalization to the key agreement, summation, and anonymous ranking

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    Semi-quantum protocols construct connections between quantum users and ``classical'' users who can only perform certain ``classical'' operations. In this paper, we present a new semi-quantum private comparison protocol based on entangled states and single particles, which does not require pre-shared keys between the ``classical'' users to guarantee the security of their private data. By utilizing multi-particle entangled states and single particles, our protocol can be easily extended to multi-party scenarios to meet the requirements of multiple ``classical'' users who want to compare their private data. The security analysis shows that the protocol can effectively prevent attacks from outside eavesdroppers and adversarial participants. Besides, we generalize the proposed protocol to other semi-quantum protocols such as semi-quantum key agreement, semi-quantum summation, and semi-quantum anonymous ranking protocols. We compare and discuss the proposed protocols with previous similar protocols. The results show that our protocols satisfy the demands of their respective counterparts separately. Therefore, our protocols have a wide range of application scenarios.Comment: 19 pages 5 table

    A Diffie-Hellman quantum session key establishment protocol without entanglement

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    In 2016 and 2017, Shi et al first proposed two protocols for the communication parties to establish a quantum session key. Both work by rotating the angle of one communicator’s private key on the other party\u27s quantum public key. In their approaches, the session key shared by each pair of communicators is fixed after the key generation phase. Thereafter, the key used in each communication does not change, but for security consideration, the session key should be changed in every time usage. In other words, those key agreement protocols do not satisfy the requirement of key security. In view of this, this paper develops a quantum session key establishment based on the Diffie-Hermann style key exchange to produce different quantum session keys in each communications. After analysis, we confirm that our method can resist various attacks and is therefore secure

    Group authentication protocols for Internet of Things (IoT) – QoS and Security Properties Evaluation

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    Trabalho de conclusão de curso (graduação)—Universidade de Brasília, Faculdade de Tecnologia, 2016.The objective of this work is to provide an overview on group authentication protocols for Internet of Things (IoT) and to propose two new group protocols. Both protocols perform authentication and key agreement among a group of devices and a Mobility Management Entity (MME) and aim performance improvements, ensuring a robust security and anonymity protection. One scheme is based on both Elliptical Curves Diffie-Hellman protocol and bilinear pairing and the other is a lightweight symmetric protocol based on Shamir’s secret. Additionally, both protocols have their performance and security objectives accomplishment analyzed and compared with other works already proposed in the literature. The performance analysis and comparison comprises communication, computational, verification and storage costs. Some of the security features analyzed are forward/backward secrecy (FS/BS), anonymity and resistance to several attacks. Finally, the protocols were formally validated by AVISPA tool

    Security for network services delivery of 5G enabled device-to-device communications mobile network

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    The increase in mobile traffic led to the development of Fifth Generation (5G) mobile network. 5G will provide Ultra Reliable Low Latency Communication (URLLC), Massive Machine Type Communication (mMTC), enhanced Mobile Broadband (eMBB). Device-to-Device (D2D) communications will be used as the underlaying technology to offload traffic from 5G Core Network (5GC) and push content closer to User Equipment (UE). It will be supported by a variety of Network Service (NS) such as Content-Centric Networking (CCN) that will provide access to other services and deliver content-based services. However, this raises new security and delivery challenges. Therefore, research was conducted to address the security issues in delivering NS in 5G enabled D2D communications network. To support D2D communications in 5G, this thesis introduces a Network Services Delivery (NSD) framework defining an integrated system model. It incorporates Cloud Radio Access Network (C-RAN) architecture, D2D communications, and CCN to support 5G’s objectives in Home Network (HN), roaming, and proximity scenarios. The research explores the security of 5G enabled D2D communications by conducting a comprehensive investigation on security threats. It analyses threats using Dolev Yao (DY) threat model and evaluates security requirements using a systematic approach based on X.805 security framework. Which aligns security requirements with network connectivity, service delivery, and sharing between entities. This analysis highlights the need for security mechanisms to provide security to NSD in an integrated system, to specify these security mechanisms, a security framework to address the security challenges at different levels of the system model is introduced. To align suitable security mechanisms, the research defines underlying security protocols to provide security at the network, service, and D2D levels. This research also explores 5G authentication protocols specified by the Third Generation Partnership Project (3GPP) for securing communication between UE and HN, checks the security guarantees of two 3GPP specified protocols, 5G-Authentication and Key Agreement (AKA) and 5G Extensive Authentication Protocol (EAP)-AKA’ that provide primary authentication at Network Access Security (NAC). The research addresses Service Level Security (SLS) by proposing Federated Identity Management (FIdM) model to integrate federated security in 5G, it also proposes three security protocols to provide secondary authentication and authorization of UE to Service Provider (SP). It also addresses D2D Service Security (DDS) by proposing two security protocols that secure the caching and sharing of services between two UEs in different D2D communications scenarios. All protocols in this research are verified for functional correctness and security guarantees using a formal method approach and semi-automated protocol verifier. The research conducts security properties and performance evaluation of the protocols for their effectiveness. It also presents how each proposed protocol provides an interface for an integrated, comprehensive security solution to secure communications for NSD in a 5G enabled D2D communications network. The main contributions of this research are the design and formal verification of security protocols. Performance evaluation is supplementary

    Lightweight Three-Factor Authentication and Key Agreement Protocol for Internet-Integrated Wireless Sensor Networks

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    Wireless sensor networks (WSNs) will be integrated into the future Internet as one of the components of the Internet of Things, and will become globally addressable by any entity connected to the Internet. Despite the great potential of this integration, it also brings new threats, such as the exposure of sensor nodes to attacks originating from the Internet. In this context, lightweight authentication and key agreement protocols must be in place to enable end-to-end secure communication. Recently, Amin et al. proposed a three-factor mutual authentication protocol for WSNs. However, we identified several flaws in their protocol. We found that their protocol suffers from smart card loss attack where the user identity and password can be guessed using offline brute force techniques. Moreover, the protocol suffers from known session-specific temporary information attack, which leads to the disclosure of session keys in other sessions. Furthermore, the protocol is vulnerable to tracking attack and fails to fulfill user untraceability. To address these deficiencies, we present a lightweight and secure user authentication protocol based on the Rabin cryptosystem, which has the characteristic of computational asymmetry. We conduct a formal verification of our proposed protocol using ProVerif in order to demonstrate that our scheme fulfills the required security properties. We also present a comprehensive heuristic security analysis to show that our protocol is secure against all the possible attacks and provides the desired security features. The results we obtained show that our new protocol is a secure and lightweight solution for authentication and key agreement for Internet-integrated WSNs

    IST Austria Thesis

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    Many security definitions come in two flavors: a stronger “adaptive” flavor, where the adversary can arbitrarily make various choices during the course of the attack, and a weaker “selective” flavor where the adversary must commit to some or all of their choices a-priori. For example, in the context of identity-based encryption, selective security requires the adversary to decide on the identity of the attacked party at the very beginning of the game whereas adaptive security allows the attacker to first see the master public key and some secret keys before making this choice. Often, it appears to be much easier to achieve selective security than it is to achieve adaptive security. A series of several recent works shows how to cleverly achieve adaptive security in several such scenarios including generalized selective decryption [Pan07][FJP15], constrained PRFs [FKPR14], and Yao’s garbled circuits [JW16]. Although the above works expressed vague intuition that they share a common technique, the connection was never made precise. In this work we present a new framework (published at Crypto ’17 [JKK+17a]) that connects all of these works and allows us to present them in a unified and simplified fashion. Having the framework in place, we show how to achieve adaptive security for proxy re-encryption schemes (published at PKC ’19 [FKKP19]) and provide the first adaptive security proofs for continuous group key agreement protocols (published at S&P ’21 [KPW+21]). Questioning optimality of our framework, we then show that currently used proof techniques cannot lead to significantly better security guarantees for "graph-building" games (published at TCC ’21 [KKPW21a]). These games cover generalized selective decryption, as well as the security of prominent constructions for constrained PRFs, continuous group key agreement, and proxy re-encryption. Finally, we revisit the adaptive security of Yao’s garbled circuits and extend the analysis of Jafargholi and Wichs in two directions: While they prove adaptive security only for a modified construction with increased online complexity, we provide the first positive results for the original construction by Yao (published at TCC ’21 [KKP21a]). On the negative side, we prove that the results of Jafargholi and Wichs are essentially optimal by showing that no black-box reduction can provide a significantly better security bound (published at Crypto ’21 [KKPW21c])
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