45 research outputs found
Factors Impacting Key Management Effectiveness in Secured Wireless Networks
The use of a Public Key Infrastructure (PKI) offers a cryptographic solution that can overcome many, but not all, of the MANET security problems. One of the most critical aspects of a PKI system is how well it implements Key Management. Key Management deals with key generation, key storage, key distribution, key updating, key revocation, and certificate service in accordance with security policies over the lifecycle of the cryptography. The approach supported by traditional PKI works well in fixed wired networks, but it may not appropriate for MANET due to the lack of fixed infrastructure to support the PKI. This research seeks to identify best practices in securing networks which may be applied to new network architectures
High-Throughput Screening of Acyl-CoA Thioesterase I Mutants Using a Fluid Array Platform
Screening target microorganisms from a mutated recombinant library plays a crucial role in advancing synthetic biology and metabolic engineering. However, conventional screening tools have several limitations regarding throughput, cost, and labor. Here, we used the fluid array platform to conduct high-throughput screening (HTS) that identified Escherichia coli ???TesA thioesterase mutants producing elevated yields of free fatty acids (FFAs) from a large (106) mutant library. A growth-based screening method using a TetA-RFP fusion sensing mechanism and a reporter-based screening method using high-level FFA producing mutants were employed to identify these mutants via HTS. The platform was able to cover >95% of the mutation library, and it screened target cells from many arrays of the fluid array platform so that a post-analysis could be conducted by gas chromatography. The ???TesA mutation of each isolated mutant showing improved FFA production in E. coli was characterized, and its enhanced FFA production capability was confirmed
All-rounder: A flexible DNN accelerator with diverse data format support
Recognizing the explosive increase in the use of DNN-based applications,
several industrial companies developed a custom ASIC (e.g., Google TPU, IBM
RaPiD, Intel NNP-I/NNP-T) and constructed a hyperscale cloud infrastructure
with it. The ASIC performs operations of the inference or training process of
DNN models which are requested by users. Since the DNN models have different
data formats and types of operations, the ASIC needs to support diverse data
formats and generality for the operations. However, the conventional ASICs do
not fulfill these requirements. To overcome the limitations of it, we propose a
flexible DNN accelerator called All-rounder. The accelerator is designed with
an area-efficient multiplier supporting multiple precisions of integer and
floating point datatypes. In addition, it constitutes a flexibly fusible and
fissionable MAC array to support various types of DNN operations efficiently.
We implemented the register transfer level (RTL) design using Verilog and
synthesized it in 28nm CMOS technology. To examine practical effectiveness of
our proposed designs, we designed two multiply units and three state-of-the-art
DNN accelerators. We compare our multiplier with the multiply units and perform
architectural evaluation on performance and energy efficiency with eight
real-world DNN models. Furthermore, we compare benefits of the All-rounder
accelerator to a high-end GPU card, i.e., NVIDIA GeForce RTX30390. The proposed
All-rounder accelerator universally has speedup and high energy efficiency in
various DNN benchmarks than the baselines
A Secure and Efficient Audit Mechanism for Dynamic Shared Data in Cloud Storage
With popularization of cloud services, multiple users easily share and update their data through cloud storage. For data integrity and consistency in the cloud storage, the audit mechanisms were proposed. However, existing approaches have some security vulnerabilities and require a lot of computational overheads. This paper proposes a secure and efficient audit mechanism for dynamic shared data in cloud storage. The proposed scheme prevents a malicious cloud service provider from deceiving an auditor. Moreover, it devises a new index table management method and reduces the auditing cost by employing less complex operations. We prove the resistance against some attacks and show less computation cost and shorter time for auditing when compared with conventional approaches. The results present that the proposed scheme is secure and efficient for cloud storage services managing dynamic shared data
Survey of Overlay Multicast Technology
IP Multicast is a technique that can transmit one copy of data traffic to multiple receivers at one time. Because it can greatly save the network bandwidth consumption as well as many applications are inherently multicast-based, it has been a research focus since the idea was proposed. However, because of many reasons, such as management, security, inter-domain routing,etc, it has not been widely deployed. Recently, many researchers have put their research focus on Overlay Multicast. In Overlay Multicast, the data replication, multicast routing, group management, and other functions are all achieved at application layer. Because it does not require to change the current Internet infrastructure, it can easily be deployed. Since the idea was proposed, many overlay multicast ideas have been proposed. They differ in multicast tree formation, underlayer support, etc. In this paper, we did a systematic research on available overlay multicast technologies. We classify them based on their different characteristics and present the different ideas of these protocols.