33288907
Practical Pay-TV Scheme Using Traitor Tracing Scheme for Multiple Channels
A Pay-TV scheme broadcasts a set of services or streams instead of one. That is, a pay-TV scheme is a specific application of a broadcast encryption scheme in which the secret to be broadcast is associated with a number of services. For example, a pay-TV broadcaster offers various channels such as a sports channel, a movie channel, and so on. A traitor tracing scheme is a variant of a broadcast encryption scheme, so can be applied to construct a pay-TV scheme. However, because most known traitor tracing schemes deal with the broadcast of a single stream, a direct extension to multiple streams is too inefficient, i.e., direct extension to an m-stream case would involve an m-fold increase in the user's secret keys. In other words, if the number of streams to be sent increases, the number of secret keys each user must store in a secure memory also linearly increases. Therefore, we require a specific traitor tracing scheme which can be efficiently applied to a pay-TV scheme. We propose a new traitor tracing scheme for multiple channels and its application to a pay-TV scheme. The number of secret keys each user must store in a secure memory is just one regardless of the number of channels and it cannot be changed. Our scheme has a revocation property, i.e., we can revoke some users without redistributing a new secret key to other un-revoked users. Our scheme also provides a so called holding property – we can revoke some users and un-revoke them without redistribution of new keys after some period. This is very useful in a pay-TV scheme since a user may wish to un-subscribe from a channel for some periods and re-subscribe again later. Moreover, our pay-TV scheme is based on a public key traitor tracing scheme. Therefore, any content provider can send encrypted data to users with the public key the system manager provides. Our scheme can also be extended to provide asymmetric property and be secure against the adaptive chosen ciphertext attack.
12552933
TTS without Revocation Capability Secure Against CCA2
A traitor tracing scheme (TTS) deters traitors from giving away their secret keys to decrypt the transmitted data by enabling the system manager to trace at least one of the traitors who participated in the construction of a pirate decoder after confiscating it. In an asymmetric scheme, the system manager is also under suspicion, so the system manager must convince a judge of the implication of the traitors. Recently, Kiayias and Yung proposed an asymmetric public key traitor tracing scheme [13]. However, their scheme does not provide CCA2 security even if a single user is a traitor. That is, their scheme is secure against adaptive chosen ciphertext (CCA2) attack only when there is no traitor. In this paper, we first introduce the security notion against CCA2 attack in a traitor tracing scheme with no revocation capability. This notion is somewhat different from the traditional security notion against CCA2 attack in a two-party encryption scheme [5]. To the best of our knowledge, no security notion against CCA2 attack in a traitor tracing scheme with no revocation capability has been presented. In addition, we modify the Kiayias and Yung’s scheme to achieve security against CCA2 attack under the decision Diffie-Hellman assumption and the collision-resistant hash function assumption.
11427398
New Key Recovery in WAKE Protocol
Wireless authentication and key establishment (WAKE) protocols are essential in mobile communications. The key recovery mechanism may also be required in mobile communication systems for the investigation of serious crimes and for national security. Recently some protocols that give key recovery in the WAKE protocol have been published. In this paper we propose new key recovery protocols that improve previous protocols in security and efficiency.
36481442
An Efficient Revocation Scheme for Stateless Receivers
A revocation scheme for stateless receivers enables the center to deliver information securely to the legitimate users over a public channel, where the receivers do not update their state from session to session. In this paper, we propose an efficient revocation scheme for stateless receivers. Our scheme uses a logical hierarchical key tree. Among previously proposed revocation schemes for stateless receivers, the SD scheme [10] is very efficient with respect to message length and Asano’s schemes [1] are very efficient with respect to key storage. Using a binary key tree, our scheme has the same message length as the SD scheme and requires the storage of log n keys, whereas the SD scheme requires the storage of \(\frac{1}{2}\log ^{2} n + \frac{1}{2}\log n + 1\) keys. Using an a-ary key tree, our scheme has the same key storage as Asano’s method 2 and requires a message length of at most 2r–1, whereas Asano’s schemes require a message length of at most \(r(\frac{\log\frac{n}{r}}{\log a} +1)\). Therefore, our scheme is more efficient than the SD scheme and Asano’s schemes.
7848399
Model-driven software product lines
Model-driven software product lines combine the abstraction capability of Model Driven Software Development (MDSD) and the variability management capability of Software Product Line Engineering (SPLE). This short contribution motivates the idea of model-driven software product lines and briefly explains the concepts underlying feature-based model templates, which is a particular technique for modeling software product lines.
9179095
fmp and fmp2rsm: eclipse plug-ins for modeling features using model templates
Feature-based model templates have been proposed as a technique for modeling software product lines. We describe a set of tools supporting the technique, namely a feature model editor and feature configurator, and a model-template editor, processor, and verifier.
9249416
Distributed Microarchitectural Protocols in the TRIPS Prototype Processor
Growing on-chip wire delays will cause many future microarchitectures to be distributed, in which hardware resources within a single processor become nodes on one or more switched micronetworks. Since large processor cores will require multiple clock cycles to traverse, control must be distributed, not centralized. This paper describes the control protocols in the TRIPS processor, a distributed, tiled microarchitecture that supports dynamic execution. It details each of the five types of reused tiles that compose the processor, the control and data networks that connect them, and the distributed microarchitectural protocols that implement instruction fetch, execution, flush, and commit. We also describe the physical design issues that arose when implementing the microarchitecture in a 170M transistor, 130nm ASIC prototype chip composed of two 16-wide issue distributed processor cores and a distributed 1MB non-uniform (NUCA) on-chip memory system
44446781
One-dimensional simplex search
Abstract We present a one-dimensional simplex search algorithm. We show that it converges to an optimum of any unimodal function and can be made to perform like the well known Golden Section search. We point out why our search would be preferable over other search algorithms when used as a subroutine in multidimensional search.
41189424
SQUIRE: Sequential pattern mining with quantities
Discovering sequential patterns is an important problem for many applications. Existing algorithms find qualitative sequential patterns in the sense that only items are included in the patterns. However, for many applications, such as business and scientific applications, quantitative attributes are often recorded in the data, which are ignored by existing algorithms. Quantity information included in the mined sequential patterns can provide useful insight to the users. 
 
In this paper, we consider the problem of mining sequential patterns with quantities. We demonstrate that naive extensions to existing algorithms for sequential patterns are inefficient, as they may enumerate the search space blindly. To alleviate the situation, we propose hash filtering and quantity sampling techniques that significantly improve the performance of the naive extensions. Experimental results confirm that compared with the naive extensions, these schemes not only improve the execution time substantially but also show better scalability for sequential patterns with quantities.