12329362
Fault Attacks for CRT Based RSA: New Attacks, New Results, and New Countermeasures
Nowadays RSA using Chinese Remainder Theorem (CRT) is widely used in practical applications. However there is a very powerful attack against it with a fault injection during one of its exponentiations. Many countermeasures were proposed but almost all of them are proven to be insecure. In 2005, two new countermeasures were proposed. However they still have a weakness. The final signature is stored in a memory after CRT combination and there is an error-check routine just after CRT combination. Therefore, if an attacker can do a double-fault attack that gives the first fault during one of the exponentiation and the other to skip the error-checking routine, then he can succeed in breaking RSA. In this paper, we show this can be done with the concrete result employing a glitch attack and propose a simple and almost cost-free method to defeat it.
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.
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.
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.
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.
6889249
Discrete differential error metric for surface simplification
In this paper we propose a new discrete differential error metric for surface simplification. Many surface simplification algorithms have been developed in order to produce rapidly high quality approximations of polygonal models, and the quadric error metric based on the distance error is the most popular and successful error metric so far Even though such distance based error metrics give visually pleasing results with a reasonably fast speed, it is hard to measure an accurate geometric error on a highly curved and thin region since the error measured by the distance metric on such a region is usually small and causes a loss of visually important features. To overcome such a drawback, we define a new error metric based on the theory of local differential geometry in such a way that the first and the second order discrete differentials approximated locally on a discrete polygonal surface are integrated into the usual distance error metric. The benefits of our error metric are preservation of sharp feature regions after a drastic simplification, small geometric errors, and fast computation comparable to the existing methods.
12867787
I Am Fine but You Are Not: Optimistic Bias and Illusion of Control on Information Security
Information security is a critically important issue in current networked business and work environments. While there is extensive publicity on the increasing incidents of numerous information security breaches and their serious consequences, recent surveys and research on information security repeatedly identify the low levels of user and managerial awareness as a key obstacle to achieving a good information security posture. The main motivation of our research emanates from this contradicting phenomenon: increased vulnerability to information security breaches yet the low level of user and managerial awareness on information security threats. In this research, we study this dissonance by addressing a cognitive bias, optimistic bias, that is, the tendency of people to believe that negative events are less likely to happen to them than to others and that positive events are more likely to happen to them than others. Using a survey, we find that users demonstrate optimistic bias in their risk perceptions associated with information security. This self-serving bias is also found to be related to a perception of controllability with information security threats. These results have practical implications for designing security awareness programs by suggesting that risk communication and management efforts are likely to fail unless they consider this bias.
3992937
A NUCA substrate for flexible CMP cache sharing
We propose an organization for the on-chip memory system of a chip multiprocessor, in which 16 processors share a 16MB pool of 256 L2 cache banks. The L2 cache is organized as a non-uniform cache architecture (NUCA) array with a switched network embedded in it for high performance. We show that this organization can support the spectrum of degrees of sharing: unshared, in which each processor has a private portion of the cache, thus reducing hit latency, completely shared, in which every processor shares the entire cache, thus minimizing misses, and every point in between. We find the optimal degree of sharing for a number of cache bank mapping policies, and also evaluate a per-application cache partitioning strategy. We conclude that a static NUCA organization with sharing degrees of two or four work best across a suite of commercial and scientific parallel workloads. We also demonstrate that migratory, dynamic NUCA approaches improve performance significantly for a subset of the workloads at the cost of increased power consumption and complexity, especially as per-application cache partitioning strategies are applied.
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
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.