Analysis of Fast and Secure Protocol Based on Continuous-Time Markov Chain

To provide an optimal alternative to traditional Transmission Control Protocol(TCP)-based transport technologies,Aspera's Fast and Secure Protocol(FASP)is proposed as an innovative bulky data transport technology.To accurately analyse the reliability and rapidness of FASP,an automated formal technique - probabilistic model checking - is used for formally analysing FASP in this paper.First,FASP's transmission process is decomposed into three modules:the Sender,the Receiver and the transmission Channel.Each module is then modelled as a Continuous-Time Markov Chain(CTMC).Second,the reward structure for CTMC is introduced so that the reliability and rapidness can be specified with the Continuous-time Stochastic Logic(CSL).Finally,the probabilistic model checker,PRISM is used for analysing the impact of different parameters on the reliability and rapidness of FASP.The probability that the Sender finishes sending data and the Receiver successfully receives data is always 1,which indicates that FASP can transport data reliably.The result that FASP takes approximately 10 s to complete transferring the file of 1 G irrespective of the network configuration shows that FASP can transport data very quickly.Further,by the comparison of throughput between FASP and TCP under various latency and packet loss conditions,FASP's throughput is shown to be perfectly independent of network delays and robust to extreme packet loss.

Probabilistic verification of hierarchical leader election protocol in dynamic systems

Leader election protocols are fundamental for coordination problems--such as consensus--in distributed computing. Recently, hierarchical leader election protocols have been proposed for dynamic systems where processes can dynamically join and leave, and no process has global information. However, quantitative analysis of such protocols is generally lacking. In this paper, we present a probabilistic model checking based approach to verify quantitative properties of these protocols. Particularly, we employ the compositional technique in the style of assume-guarantee reasoning such that the sub-protocols for each of the two layers are verified separately and the correctness of the whole protocol is guaranteed by the assume-guarantee rules. Moreover, within this framework we also augment the proposed model with additional features such as rewards. This allows the analysis of time or energy consumption of the protocol. Experiments have been conducted to demonstrate the effectiveness of our approach.

Fairness analysis of extra-gain guilty of a non-repudiation protocol

Many traditional applications can be refined thanks to the development of blockchain technology. One of these services is non-repudiation, in which participants in a communication process cannot deny their involvement.Due to the vulnerabilities of the non-repudiation protocols, one of the parties involved in the communication can often avoid non-repudiation rules and obtain the expected information to the detriment of the interests of the other party, resulting in adverse effects. This paper studies the fairness guarantee quantitatively through probabilistic model checking. E-fairness is measured by modeling the protocol in probabilistic timed automata and verifying the appropriate property specified in the probabilistic computation tree logic. Furthermore, our analysis proposes insight for choosing suitable values for different parameters associated with the protocol so that a certain degree of fairness can be obtained. Therefore, the reverse question—for a certain degree of fairness ε, how can the protocol parameters be specified to ensure fairness—is answered.