ADS-B Data Authentication Based on ECC and X.509 Certificate

An automatic dependent surveillance- broadcast （ADS-B） system has serious security problems, and the data can be spoofed during broadcasting precise position information of aircraft. A solution of the ADS-B system data authentication based on the elliptic curve cipher （ECC） and X.509 certificate is proposed. It can avoid the key distribution problem by using the symmetric key algorithm and prevent the ADS-B data from being spoofed thoroughly. Experimental test results show that the solution is valid and appropriate in ADS-B universal access transceiver （UAT） mode.

A distributed authentication and authorization scheme for in-network big data sharing

Big data has a strong demand for a network infrastructure with the capability to support data sharing and retrieval efficiently. Information-centric networking （ICN） is an emerging approach to satisfy this demand, where big data is cached ubiquitously in the network and retrieved using data names. However, existing authentication and authorization schemes rely mostly on centralized servers to provide certification and mediation services for data retrieval. This causes considerable traffic overhead for the secure distributed sharing of data. To solve this problem, we employ identity-based cryptography （IBC） to propose a Distributed Authentication and Authorization Scheme （DAAS）, where an identity-based signature （IBS） is used to achieve distributed verifications of the identities of publishers and users. Moreover, Ciphertext-Policy Attribnte-based encryption （CP-ABE） is used to enable the distributed and fine-grained authorization. DAAS consists of three phases： initialization, secure data publication, and secure data retrieval, which seamlessly integrate authentication and authorization with the in- terest/data communication paradigm in ICN. In particular, we propose trustworthy registration and Network Operator and Authority Manifest （NOAM） dissemination to provide initial secure registration and enable efficient authentication for global data retrieval. Meanwhile, Attribute Manifest （AM） distribution coupled with automatic attribute update is proposed to reduce the cost of attribute retrieval. We examine the performance of the proposed DAAS, which shows that it can achieve a lower bandwidth cost than existing schemes.

A Novel Video Data-Source Authentication Model Based on Digital Watermarking and MAC in Multicast

A novel video data authentication model based on digital video watermarking and MAC （message authentication code） in multicast protocol is proposed in this paper, The digital watermarking which composes of the MAC of the significant vid eo content, the key and instant authentication data is embedded into the insignificant video component by the MLUT （modified look-up table） video watermarking technology. We explain a method that does not require storage of each data packet for a time, thus making receiver not vulnerable to DOS （denial of service） attack. So the video packets can be authenticated instantly without large volume buffer in the receivers. TESLA （timed efficient stream loss tolerant authentication） does not explain how to select the suitable value for d, which is an important parameter in multicast source authentication. So we give a method to calculate the key disclosure delay （number of intervals）. Simulation results show that the proposed algorithms improve the performance of data source authentication in multicast.

Optimized Algorithms for Flexible Length-Based Authenticated Skip List

With the growing trend toward using cloud storage,the problem of efficiently checking and proving data integrity needs more consideration.Many cryptography and security schemes,such as PDP(Provable Data Possession) and POR(Proofs of Retrievability) were proposed for this problem.Although many efficient schemes for static data have been constructed,only a few dynamic schemes exist,such as DPDP(Dynamic Provable Data Possession).But the DPDP scheme falls short when updates are not proportional to a fixed block size.The FlexList-based Dynamic Provable Data Possession(FlexDPDP) was an optimized scheme for DPDP.However,the update operations(insertion,remove,modification)in Flex DPDP scheme only apply to single node at a time,while multiple consecutive nodes operation is more common in practice.To solve this problem,we propose optimized algorithms for multiple consecutive nodes,which including MultiNodes Insert and Verification,MultiNodes Remove and Verification,MultiNodes Modify and Verification.The cost of our optimized algorithms is also analyzed.For m consecutive nodes,an insertion takes O(m) + O(log N) + O(log m),where N is the number of leaf nodes of FlexList,a remove takes O(log/V),and a modification is the same as the original algorithm.Finally,we compare the optimized algorithms with original FlexList through experiences,and the results show that our scheme has the higher efficiency of time and space.

云端多管理者群组共享数据中具有隐私保护的公开审计方案

随着云存储服务的广泛使用,用户数据不仅能存储在云中,并且能够由多个用户共享.为了保证云端群组共享数据的完整性,研究者提出了多项针对云端群组共享数据公开审计方案.但是,现有方案只考虑了群组用户中仅有单个群管理者的情形,并且没有考虑群组用户身份追踪过程中的陷害性问题.提出的方案中首次给出了面向多管理者群组共享数据的公开审计安全模型,并通过构造基于可撤销的群签名和(t,s)门限方案的多群管理者同态可验证群签名,设计了首个适用于多管理者群组共享数据的公开审计方案.提出的公开审计方案不仅能够实现身份隐私、可追踪性和不可陷害性等多层次的隐私保护能力,并且能很好地支持群组用户的撤销和续约.此外,方案的审计开销与群组用户数量大小无关,保证了方案的可行性和高效性.

A Private User Data Protection Mechanism in TrustZone Architecture Based on Identity Authentication

In Trust Zone architecture, the Trusted Application（TA） in the secure world does not certify the identity of Client Applications（CA） in the normal world that request data access, which represents a user data leakage risk. This paper proposes a private user data protection mechanism in Trust Zone to avoid such risks. We add corresponding modules to both the secure world and the normal world and authenticate the identity of CA to prevent illegal access to private user data. Then we analyze the system security, and perform validity and performance tests.The results show that this method can perform effective identity recognition and control of CA to protect the security of private user data. After adding authentication modules, the data operation time of system increases by about0.16 s, an acceptable price to pay for the improved security.

A Non-symmetric Digital Image Secure Communication Scheme Based on Generalized Chaos Synchronization System

Based on a generalized chaos synchronization system and a discrete Sinai map, a non-symmetric true color （RGB） digital image secure communication scheme is proposed. The scheme first changes an ordinary RGB digital image with 8 bits into unrecognizable disorder codes and then transforms the disorder codes into an RGB digital image with 16 bits for transmitting. A receiver uses a non-symmetric key to verify the authentication of the received data origin, and decrypts the ciphertext. The scheme can encrypt and decz：Fpt most formatted digital RGB images recognized by computers, and recover the plaintext almost without any errors. The scheme is suitable to be applied in network image communications. The analysis of the key space, sensitivity of key parameters, and correlation of encrypted images imply that this scheme has sound security.

Blockchain Based Redistricting with Public Participation

Redistricting is the process of grouping all census blocks within a region to form larger subdivisions, or districts. The process is typically subject to some hard rules and some (soft) preferences to improve fairness of the solution. Achieving public consensus on the fairness of proposed redistricting plans is highly desirable. Unfortunately, fair redistricting is an NP hard optimization problem. The complexity of the process makes it even more challenging to convince the public of the fairness of the proposed solution. This paper proposes a completely transparent blockchain based strategy to promote public participation in the redistricting process, to increase public confidence in the outcome of the process. The proposed approach is based on the fact that one does not have to worry about how the NP hard problem was solved, as long as it is possible for anyone to compute a “goodness” metric for the proposed plan. In the proposed approach, anyone can submit a plan along with the expected metric. Only the plan with the best claimed metric needs to be evaluated in a blockchain network.

Authoritative and Unbiased Responses to Geographic Queries

A protocol for processing geographic data is proposed to guarantee authoritative and unbiased responses to geographic queries, without the need to rely on trusted third parties. The integrity of the proposed authoritative and unbiased geographic services (AUGS) protocol is guaranteed by employing novel hash tree based authenticated data structures (ADS) in conjunction with a blockchain ledger. Hash tree based ADSes are used to incrementally compute a succinct dynamic commitments to AUGS data. A blockchain ledger is used to record 1) transactions that trigger updates to AUGS data, and 2) the updated cryptographic commitments to AUGS data. Untrusted service providers are required to provide verification objects (VOs) as proof-of-correctness of their responses to AUGS queries. Anyone with access to commitments in ledger entries can verify the proof.

Factors affecting forensic electric network frequency matching-A comprehensive study

The power system frequency fluctuations could be captured by digital recordings and extracted to compare with a reference database for forensic timestamp verification.It is known as the Electric Network Frequency(ENF)criterion,enabled by the properties of random fluctuations and intra-grid consistency.In essence,this is a task of matching a short random sequence within a long reference,whose accuracy is mainly concerned with whether this match could be uniquely correct.In this paper,we comprehensively analyze the factors affecting the reliability of ENF matching,including the length of test recording,length of reference,temporal resolution,and Signal-to-Noise Ratio(SNR).For synthetic analysis,we incorporate the first-order AutoRegressive(AR)ENF model and propose an efficient Time-Frequency Domain noisy ENF synthesis method.Then,the reliability analysis schemes for both synthetic and real-world data are respectively proposed.Through a comprehensive study,we quantitatively reveal that while the SNR is an important external factor to determine whether timestamp verification is viable,the length of test recording is the most important inherent factor,followed by the length of reference.However,the temporal resolution has little impact on performance.Finally,a practical workflow of the ENF-based audio timestamp verification system is proposed,incorporating the discovered results.