67 research outputs found

    Active Android malware analysis: an approach based on stochastic games

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    Active Malware Analysis focuses on learning the behaviors and the intentions of a malicious piece of software by interacting with it in a safe environment. The process can be formalized as a stochastic game involving two agents, a malware sample and an analyzer, that interact with opposite objectives: the malware sample tries to hide its behavior, while the analyzer aims at gaining as much information on the malware sample as possible. Our goal is to design a software agent that interacts with malware and extracts information on the behavior, learning a policy. We can then analyze different malware policies by using standard clustering approaches. In more detail, we propose a novel method to build malware models that can be used as an input to the stochastic game formulation. We empirically evaluate our method on real malware for the Android systems, showing that our approach can group malware belonging to the same families and identify the presence of possible sub-groups within such families

    Cast-as-Intended Mechanism with Return Codes Based on PETs

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    We propose a method providing cast-as-intended verifiability for remote electronic voting. The method is based on plaintext equivalence tests (PETs), used to match the cast ballots against the pre-generated encrypted code tables. Our solution provides an attractive balance of security and functional properties. It is based on well-known cryptographic building blocks and relies on standard cryptographic assumptions, which allows for relatively simple security analysis. Our scheme is designed with a built-in fine-grained distributed trust mechanism based on threshold decryption. It, finally, imposes only very little additional computational burden on the voting platform, which is especially important when voters use devices of restricted computational power such as mobile phones. At the same time, the computational cost on the server side is very reasonable and scales well with the increasing ballot size

    Efficient enhanced keyword search for encrypted document in cloud

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    A sensitive public-key searchable encryption system in the prime-order groups, which lets keyword search policies to be uttered in conjunctive, disjunctive or any monotonic Boolean formulas and realizes momentous act enhancement over existing schemes. We legally express its sanctuary, and verify that it is selectively sheltered in the standard model. Correspondingly, we instrument the wished-for outline using a hasty prototyping tool so-called Charm and conduct more than a few experiments to estimate it show. The results determine that our scheme is plentiful more proficient than the ones assembled over the composite-order groups. Keyword research is one of the most imperative, valuable, and high return activities in the search marketing field. Position for the right keywords can make or interruption your website

    Nonce-based Kerberos is a Secure Delegated AKE Protocol

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    Kerberos is one of the most important cryptographic protocols, first because it is the basisc authentication protocol in Microsoft\u27s Active Directory and shipped with every major operating system, and second because it served as a model for all Single-Sign-On protocols (e.g. SAML, OpenID, MS Cardspace, OpenID Connect). Its security has been confirmed with several Dolev-Yao style proofs, and attacks on certain versions of the protocol have been described. However despite its importance, despite its longevity, and despite the wealth of Dolev-Yao-style security proofs, no reduction based security proof has been published until now. This has two reasons: (1) All widely accepted formal models either deal with two-party protocols, or group key agreement protocols (where all entities have the same role), but not with 3-party protocols where each party has a different role. (2) Kerberos uses timestamps and nonces, and formal security models for timestamps are not well understood up to now. As a step towards a full security proof of Kerberos, we target problem (1) here: We propose a variant of the Kerberos protocol, where nonces are used instead of timestamps. This requires one additional protocol message, but enables a proof in the standard Bellare-Rogaway (BR) model. The key setup and the roles of the different parties are identical to the original Kerberos protocol. For our proof, we only require that the authenticated encryption and the message authentication code (MAC) schemes are secure. Under these assumptions we show that the probability that a client or server process oracle accepts maliciously, and the advantage of an adversary trying to distinguish a real Kerberos session key from a random value, are both negligible. One main idea in the proof is to model the Kerberos server a a public oracle, so that we do not have to consider the security of the connection client--Kerberos. This idea is only applicable to the communication pattern adapted by Kerberos, and not to other 3-party patterns (e.g. EAP protocols)

    Cloud Storage File Recoverability

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    How to Construct Rational Protocols with Nash Equilibrium Consistency in the UC framework

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    The inconsistency of Nash equilibrium of rational delegated computation scheme in the UC framework will lead to the lack of strict security proof of the protocols fundamentally. The consistency proof of Nash equilibrium between the ideal world and the real world has always been a challenge in the research field. In this paper, we analyze the Nash equilibrium according to the game model of rational delegated computation, and the ideal functionality for rational delegation of computation based on incentive-driven adversary is proposed, then we construct a rational delegated computation protocol for UC-realizing the ideal functionality. In a word, the proposed rational delegated computing protocol based on incentive-driven adversary has been proven to be secure in the universally composable framework, furthermore, we effectively solve the inconsistency problem of Nash equilibrium between the real world and the ideal world
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