Related Work Sample Clauses

Related Work. The original idea of extending the 2-party Xxxxxx-Xxxxxxx scheme [15] to the multi-party setting dates back to the classical paper of Ingemarsson et al. [19], and is followed by many works [25, 13, 20, 3, 21, 26, 22] offering various levels of complexity. However, research on provably-secure group key agreement in concrete, realistic setting is fairly new. It is only recently that Bresson et al. [12, 8, 9] have presented the first group key agreement protocols proven secure in a well-defined security model which builds on earlier model of Xxxxxxx et al. [4]. The initial work [12] assumes that group membership is static, whereas later works [8, 9] focus on the dynamic case which we do not deal with here. But one drawback of their scheme is that its round complexity is linear in the number of group members. Consequently, as group size grows large, this scheme becomes impractical particularly in a wide area network with high communication latency. More recently, Xxxx and Yung [23] have proposed the first constant-round group key agreement protocol that has been proven secure in the security model of Bresson et al. [12]. They provide a formal proof of security for the two-round protocol of Xxxxxxxxx and Xxxxxxx [13], and introduce a one-round compiler that transforms any group key agree- ment protocol secure against a passive adversary into one that is secure against an active adversary. In this protocol all group members behave in a completely symmetric manner; in a group of size n, each member sends one broadcast message per round, and computes three modular exponentiations, O(n log n) modular multiplications, O(n) signature verifica- tions, and two signature generations. While this protocol is very efficient in general, the full symmetry negatively impacts on the overall performance of the protocol in our asymmetric setting; the computational cost of a mobile host is significant in a large group, due to the number of modular multiplications and signature verifications. Most recently, Bresson and Xxxxxxxx [7] have introduced another fully-symmetric proto- col which requires two rounds of communication. Interestingly, unlike previous approaches, they construct the protocol by combining the properties of the ElGamal encryption scheme [17] with standard secret sharing techniques [24]. However, with increasing number of par- ticipants, the complexity of the protocol becomes beyond the capabilities of a small mobile device. The protocol presented by Xxxx and Xxxx...
Related Work. Members of this International Union shall also have jurisdiction of: (1) all processes and procedures for decontamination of all contaminated areas; (2) all clean-up of any type debris caused by or during the preparation and/or application of any work described in this Section.
Related Work. The Airport Authority may engage separate contractors to perform work as a part of or related to the Project (“Related Work”). The Contractor shall cooperate and coordinate with any such separate contractors, as provided in this section and in the General Conditions. If determined appropriate by the Airport Authority, a separate contractor shall have the right to monitor the construction of the Work, and the Contractor shall meet with such separate contractor at such times as the Contractor or such separate contractor deem appropriate, and the Contractor shall provide access to and accommodate representatives of such separate contractor to permit such representatives to observe the Work. If determined appropriate by the Airport Authority, the Contractor shall have the right to monitor the construction of the Related Work. The Contractor shall notify the Airport Authority immediately of any conflicts, gaps, omissions, inconsistencies, incompatibilities, delays, deficiencies or other adverse impacts (collectively, "Conflicts") which the Contractor discovers or observes at any time between or with respect to the design and/or construction of the Work and the design and/or construction of any Related Work. Such notice shall be given by the most expedient method available, with written confirmation delivered within five days after the Contractor observes or discovers such Conflict.
Related Work. Many GKA protocols [5, 11, 7, 4, 6, 3] have been pro- posed in literature, most being derived from the two-party Xxxxxx-Xxxxxxx (DH) key agreement protocol. While some are secure against passive adversaries only, others do not have a rigorous security proof. A security proof typically involves showing that an attack on a protocol can be used to solve a well-known hard problem under some standard assumptions. Provably secure protocols in a well-defined model of security were first provided by Bresson et al. [4]. Their security model extended the earlier work of Xxxxxxx et al. [1]. The number of rounds in these protocols is linear in the number of participants, thus making them unsuitable for large ad hoc networks. − Yung et al. [6] proposed the first provably-secure con- stant round GKA protocol inspired from the works of Xxxxxxxxx et al. [5]. In the same work, they also pro- posed a scalablecompiler” to transform a GKA protocol, secure against a passive adversary, into one which is secure against an active adversary. But one round in their proto- col consists of 1 broadcast and n 1 simultaneous receives by each user. Achieving this is not possible in most net- works. Also it lacks procedures to handle group dynamism. Xxxx et al. [3] proposed an efficient constant round pro- tocol where the bulk of the computation is done by one participant, thus making it efficient for heterogeneous ad hoc networks. It is provably secure in the Random Oracle model [1] but lacks perfect forward secrecy (i.e., compro- mise of long-term key compromises all past session1 keys). We propose a provably secure and efficient protocol which 1A session refers to one instance of GKA protocol execution in some group. Protocol Expo per Ui (Max Expo) Rounds (Messages) PS [11] 3 (m) m + 1 (2m − 3) No [7] log2 m + 1 log2 m (m) No [4] i + 1 m (m) Yes [6] 3 2٨ (2m) Yes [9] 2 (2m٨٨) 2٨ (m) Yes Ours 2 (m) 2٨ (m) Yes m: Number of participants
Related Work. We are aware of three other proofs of the k-set agreement lower bound. Chaudhuri, Herlihy, Lynch, and Xxxxxx [7] gave the first proof. Their proof consisted of taking the standard similarity chain argument used to prove the consensus synchronous lower bound and running that argument in k dimensions at once to construct a subset of the reachable complex to which a standard topological tool called Sperner’s Lemma can be applied to obtain the desired impossibility. While their intuition is geometrically compelling, it required quite a bit of technical machinery to nail down the details. Herlihy, Rajsbaum, and Xxxxxx [15] gave a proof closer to our “round-by- round” approach. In fact, the round operator that we define here is exactly the round operator they defined. Their connectivity proof for the reachable complex was not easy, however, and the inductive nature of the proof did not reflect the iterative nature of how the reachable complex is constructed by repeatedly ap- plying the round operator locally to a global state S. The notion of an absorbing poset used in this paper dramatically simplifies the connectivity proof. Gafni [12] gave another proof in an entirely different style. His proof is based on simple reductions between models, showing that the asynchronous model can simulate the first few rounds of the synchronous model, and thus showing that the synchronous lower bound follows from the known asynchronous impossibility result for set agreement [4,16,21]. While his notion of reduction is elegant, his proof depends on the asynchronous impossibility result, and that result is not easy to prove. We are interested in a simple, self-contained proof that gives as much insight as possible into the topological behavior of the synchronous model of computation. Round-by-round proofs that show how the 1-dimensional (graph) connec- tivity evolves in the synchronous model have been described by Aguilera and Xxxxx [1] and Moses and Xxxxxxxx [18] (the latter do it in a more general way that applies to various other asynchronous models as well) to prove consensus impossibility results. These show how to do an elegant FLP style of argument, as opposed to the more involved backward inductive argument of the standard proofs [10,8,9]. They present a (graph) connectivity proof of the successors of a global state. Thus, our proofs are similar to this strategy in the particular case of k = 1, but give additional insights because they show more general ways of organizing these ...
Related Work. Our first major influence is that of conditional phrase-based models. An early approach by Deng and Xxxxx (2005) changed the parameterization of the traditional word-based HMM model, modeling subsequent words from the same state using a bi- gram model. However, this model changes only the parameterization and not the set of possible align- ments. More closely related are the approaches of Xxxxx´ III and Marcu (2004) and XxXxxx et al. (2006), which allow phrase-to-phrase alignments between the source and target domain. As DeN- ero warns, though, an unconstrained model may overfit using unusual segmentations. Interestingly, the phrase-based hidden semi-Markov model of Andre´s-Xxxxxx and Xxxx (2009) does not seem to encounter these problems. We suspect two main causes: first, the model interpolates with Model 1 (Xxxxx et al., 1994), which may help prevent over- fitting, and second, the model is monotonic, which screens out many possible alignments. Monotonic- ity is generally undesirable, though: almost all par- allel sentences exhibit some reordering phenomena, even when languages are syntactically very similar. The second major inspiration is alignment by agreement by Liang et al. (2006). Here, soft inter- section between the forward (F→E) and backward in the backward direction. However, this is not pos- sible in a word-based HMM where each observa- tion must be generated by a single state. Agreement tends to encourage 1-to-1 alignments with very high precision and but lower recall. As each word align- ment acts as a constraint on phrase extraction, the phrase-pairs obtained from those alignments have high recall and low precision.
Related Work. As seen in Chapter 3, GPGPU programming models such as CUDA and OpenCL expose application developers to a relatively abstract model of an SPMD many-core architecture. However, platform-specific details remain largely exposed: it is critical to utilize the hardware resources efficiently in order to achieve high performance. So far, the practice of GPU programming has been dominated by heroic porting and tuning efforts, resulting in a large number of application-specific studies. We survey different aspects of the compilation challenge for GPUs: performance modeling and tuning considerations; programming models; polyhedral approaches to GPU compilation; exploration of the low-level issues related to vectorization for short-SIMD architectures such as the ARM Mali GPU; and finally linking these issues with the complete code generation flow of the CARP project through the concept of split compilation.