The QUIC Fix for Optimal Video Streaming

Within a few years of its introduction, QUIC has gained traction: a significant chunk of traffic is now delivered over QUIC. The networking community is actively engaged in debating the fairness, performance, and applicability of QUIC for various use cases, but these debates are centered around a narrow, common theme: how does the new reliable transport built on top of UDP fare in different scenarios? Support for unreliable delivery in QUIC remains largely unexplored. The option for delivering content unreliably, as in a best-effort model, deserves the QUIC designers' and community's attention. We propose extending QUIC to support unreliable streams and present a simple approach for implementation. We discuss a simple use case of video streaming---an application that dominates the overall Internet traffic---that can leverage the unreliable streams and potentially bring immense benefits to network operators and content providers. To this end, we present a prototype implementation that, by using both the reliable and unreliable streams in QUIC, outperforms both TCP and QUIC in our evaluations.Comment: Published to ACM CoNEXT Workshop on the Evolution, Performance, and Interoperability of QUIC (EPIQ

A Study of Selective Motor Fitness Components Empowers On Playing Ability among Low and High Performers of State Level Football Players

Motor fitness is a present aptitude for physical skills, includes strength and co-ordination enriches today’s Manpower in players performance.  The study focuses on selected motor fitness components to ensure the playing ability among low and high performers of State level Football players. To achieve this study, One hundred and fifty men Football players were randomly selected as subjects from Tamilnadu State level men Football Tournament held at Chennai in 2008-09. Their age ranged from20 to 25 years. Selected subjects were classified into three equal groups of each fifty members. Group 1 served as -Chennai Team, Group-II as Salem and Coimbatore Team and Group III Trichy and Madurai Team. All the subjects were oriented the purpose of the test and procedure of conducting this test. Regular activities and training were given that aplomb the player’s ability to perform the game. Questionnaire preparation was also done by our Research Scholar with the reference to the review of the literature. The investigator has provided onto the following selected motor fitness variables such as Cardio-vascular Endurance, Speed, Agility and Explosive Power. The data is collected with the help of five PhD Scholars, Department of Physical Education who were well versed with the conduct of test and collections under the direct supervision of our Research Scholar. Resulting data will be collected before and after the competition and statistically analyzed using ANOVA and DMRT. Hence the study concluded that playing ability solely depends on the physical fitness, stress free mind more than that it relates the socio-economic status to perform the better strategy of playing games.Â

Performance Characterization of NVMe Flash Devices with Zoned Namespaces (ZNS)

The recent emergence of NVMe flash devices with Zoned Namespace support, ZNS SSDs, represents a significant new advancement in flash storage. ZNS SSDs introduce a new storage abstraction of append-only zones with a set of new I/O (i.e., append) and management (zone state machine transition) commands. With the new abstraction and commands, ZNS SSDs offer more control to the host software stack than a non-zoned SSD for flash management, which is known to be complex (because of garbage collection, scheduling, block allocation, parallelism management, overprovisioning). ZNS SSDs are, consequently, gaining adoption in a variety of applications (e.g., file systems, key-value stores, and databases), particularly latency-sensitive big-data applications. Despite this enthusiasm, there has yet to be a systematic characterization of ZNS SSD performance with its zoned storage model abstractions and I/O operations. This work addresses this crucial shortcoming. We report on the performance features of a commercially available ZNS SSD (13 key observations), explain how these features can be incorporated into publicly available state-of-the-art ZNS emulators, and recommend guidelines for ZNS SSD application developers. All artifacts (code and data sets) of this study are publicly available at https://github.com/stonet-research/NVMeBenchmarks.Comment: Paper to appear in the https://clustercomp.org/2023/program

Performance Characterization of NVMe Flash Devices with Zoned Namespaces (ZNS)

The recent emergence of NVMe flash devices with Zoned Namespace support, ZNS SSDs, represents a significant new advancement in flash storage. ZNS SSDs introduce a new storage abstraction of append-only zones with a set of new I/O (i.e., append) and management (zone state machine transition) commands. With the new abstraction and commands, ZNS SSDs offer more control to the host software stack than a non-zoned SSD for flash management, which is known to be complex (because of garbage collection, scheduling, block allocation, parallelism management, overprovisioning). ZNS SSDs are, consequently, gaining adoption in a variety of applications (e.g., file systems, key-value stores, and databases), particularly latency-sensitive big-data applications. Despite this enthusiasm, there has yet to be a systematic characterization of ZNS SSD performance with its zoned storage model abstractions and I/O operations. This work addresses this crucial shortcoming. We report on the performance features of a commercially available ZNS SSD (13 key observations), explain how these features can be incorporated into publicly available state-of-the-art ZNS emulators, and recommend guidelines for ZNS SSD application developers. All artifacts (code and data sets) of this study are publicly available at https://github.com/stonet-research/NVMeBenchmarks

Dissecting Bitcoin and Ethereum Transactions: On the Lack of Transaction Contention and Prioritization Transparency in Blockchains

In permissionless blockchains, transaction issuers include a fee to incentivize miners to include their transaction. To accurately estimate this prioritization fee for a transaction, transaction issuers (or blockchain participants, more generally) rely on two fundamental notions of transparency, namely contention and prioritization transparency. Contention transparency implies that participants are aware of every pending transaction that will contend with a given transaction for inclusion. Prioritization transparency states that the participants are aware of the transaction or prioritization fees paid by every such contending transaction. Neither of these notions of transparency holds well today. Private relay networks, for instance, allow users to send transactions privately to miners. Besides, users can offer fees to miners via either direct transfers to miners' wallets or off-chain payments -- neither of which are public. In this work, we characterize the lack of contention and prioritization transparency in Bitcoin and Ethereum resulting from such practices. We show that private relay networks are widely used and private transactions are quite prevalent. We show that the lack of transparency facilitates miners to collude and overcharge users who may use these private relay networks despite them offering little to no guarantees on transaction prioritization. The lack of these transparencies in blockchains has crucial implications for transaction issuers as well as the stability of blockchains. Finally, we make our data sets and scripts publicly available.Comment: This is a pre-print of our paper accepted to appear to the Financial Cryptography and Data Security 2023 (FC '23

Understanding Blockchain Governance: Analyzing Decentralized Voting to Amend DeFi Smart Contracts

Smart contracts are contractual agreements between participants of a blockchain, who cannot implicitly trust one another. They are software programs that run on top of a blockchain, and we may need to change them from time to time (e.g., to fix bugs or address new use cases). Governance protocols define the means for amending or changing these smart contracts without any centralized authority. They distribute instead the decision-making power to every user of the smart contract: Users vote on accepting or rejecting every change. The focus of this work is to evaluate whether, how, and to what extent these protocols ensure decentralized governance, the fundamental tenet of blockchains, in practice. This evaluation is crucial as smart contracts continue to transform our key, traditional, centralized institutions, particularly banking and finance. In this work, we review and characterize decentralized governance in practice, using Compound -- one of the widely used governance protocols -- as a case study. We reveal a high concentration of voting power in Compound: 10 voters hold together 57.86% of the voting power. Although proposals to change or amend the protocol (or, essentially, the application they support) receive, on average, a substantial number of votes (i.e., 89.39%) in favor, they require fewer than three voters to obtain 50% or more votes. We show that voting on Compound governance proposals can be unfairly expensive for small token holders, and also discover voting coalitions that can further marginalize these users. We plan on publishing our scripts and data set on GitHub to support reproducible research.Comment: We have submitted this work for publication and are currently awaiting a decisio

An Efficient Hierarchical Multi-Authority Attribute Based Encryption Scheme for Profile Matching using a Fast Ate Pairing in Cloud Environment

In cloud environment, profile matching is a key technique in applications such as health care and social networks. Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is suitable technique for data sharing in such environments. In this paper, we propose an asymmetric pairing based Hierarchical Multi-Authority CP-ABE (HM-CP-ABE) construction for profile matching. We utilize the fast Ate pairing to make the proposed HM-CP-ABE scheme efficient. The performance analysis of the proposed scheme shows improved efficiency in terms of computational costs for initialization, key generation and encryption using ELiPS library when compared with existing works

Secure Data Communication using File Hierarchy Attribute Based Encryption in Wireless Body Area Networks

Wireless Body Area Networks (WBANs) play an important role in healthcare system by enabling medical experts to guide patients without measuring face-to-face. The unauthorized access of medical data from WBAN controller as well as the unreliable data communication may leads to risk for patients life. Currently, Chunqiang Hu et al., [1] proposed a data communication protocol by using Ciphertext-Policy Attribute-Based Encryption (CP-ABE) for a single file. The major limitation of Chunqiang Hu et al., [1] is that as the number of files increases, CP-ABE will suffer from parameters such as message size, energy consumption and computation cost. This paper proposes a more secure and efficient data communication protocol for WBANs by using an efficient File Hierarchy CP-ABE (FH-CP-ABE). We propose a more efficient Secure and Efficient data communication protocol for WBANs by using an efficient File Hierarchy CP-ABE (FH-CP-ABE). We use the integrated access structure which is a combination of two or more access structures and with the hierarchical files are encrypted. We evaluate the performance analysis of the proposed data communication protocol in terms of message size, energy consumption, computation cost and compared with Chunqiang Hu et al., [1] while the number of files increases