Smart grids are a combination of traditional power system engineering as well as information and communications technology. Smart grid terminals provide convenient services to users by aggregating their data in real time. However, terminals can derive user privacy information from real-time data on smart devices. Therefore, security data aggregation has been widely studied in the field of smart grid. Most existing schemes are one-dimensional data aggregation or rely on a trusted third party. In reality, multidimensional data (such as a user’s electricity consumption or user’s main usage time, etc.) makes sense for terminals to flexibly adjust supply and demand strategies. In this paper, we propose an efficient and secure multidimensional data aggregation scheme that supports batch validation without a trusted third party. Firstly, we apply the Chinese remainder theorem to encode the user’s multidimensional data and realize the independence of each dimension in terminal decryption. Secondly, we adopt a secure key negotiation protocol that does not require a trusted third party. Finally, based on paillier homomorphic encryption and bilinear pairing, we construct an encryption scheme that can reuse the key and blind factor and support batch verification. The analysis results show that our scheme is secure for users’ privacy protection. Experimental results show that, compared with existing 1 dimensional aggregation schemes, our scheme has almost no growth in computational overhead for terminal decryption.

Smart grid is a combination of traditional power system engineering and information and communication technology. Smart grid provides users with convenient services through real-time data updates. Multi-dimensional data aggregation can be more flexible for statistical analysis of electricity information. However, most of the existing multi-dimensional data aggregation schemes require the participation of a trusted third party and do not support fault tolerance. In this paper, we propose a fault-tolerant data aggregation scheme supporting fine-grained linear operations in smart grid. Firstly, we used the Chinese remainder theorem to encode the user’s multi-dimensional data and the corresponding weights. Secondly, we construct a privacy-preserving data aggregation scheme without a trusted third party, by combining paillier homomorphic encryption scheme and a secure key agreement protocol. Finally, we use the extended Shamir secret sharing scheme to construct a fault-tolerant data aggregation scheme that supports the reuse of shared key shares. Security analysis results show that our scheme satisfies semantic security and user data privacy protection. Experimental results show that compared with the existing multidimensional data aggregation schemes that require a trusted third party, our scheme does not increase additional computation and communication overhead.

As the Internet of Things (IoT) is booming, the transmission speed of data in the network is getting more and more attention. Network coding is an effective technique to improve network throughput. In network coding, the encoded packets must be integrity-checked to prevent pollution attacks. Some linearly homomorphic signature schemes based on bilinear pairs have been used to check the integrity of packets, and so far the scheme LZL20 is the most efficient signature scheme among them. Here, we first analyze the security model and signature structure of LZL20, and find that there is a security vulnerability in the scheme. Experiments show that for a 12~18 KB file, our signature forgery algorithm can forge a message/signature pair with 100% probability within 3~5 ms. Then, we construct a linearly homomorphic signature scheme with higher signature efficiency and shorter signature length. In random oracle model, we proved the scheme is existentially-unforgeable under adaptive chosen message attacks. We theoretically analyze our signature length to be 320 bits shorter than LZL20. Finally, we implement our scheme, and for a 12~18 KB file, experiments show that the signature time of our scheme is 60.93%~62.59% of that of LZL20.

Compared with traditional wireless sensor networks, mobile crowdsensing networks have advantages of low cost, easy maintenance, and high scalability, which will play a role in city-level data sensing scenarios in the future. So far, linear homomorphic signatures based on Public Key Instruction,identity, as well as certificateless, have been proposed in wireless sensor networks to resist the data contamination. However, these signature schemes can’t perform finer-grained signature verification, and these signature schemes do not realize the separation of users’ sensitive information from their data. To solve the above problems, we design an attribute-based linear homomorphic signature scheme for large-scale wireless network built with mobile smart devices. First, we give the definition of the attribute-based linear homomorphic signature scheme based on key policy (KP-ABLHS). Second, we construct KP-ABLHS by incorporating attribute-based signature and linear homomorphic coding signature scheme. Finally, we prove our protocol is secure in random oracle model (ROM) and use Python pairing-based cryptography library (pypbc) to implement the scheme. The experimental results show that our scheme is as efficient as Li et al.’s scheme and has the advantage of signing the set of attributes, while the efficiency of our scheme is significantly better than that of scheme Boneh et al.’s scheme.

With the surge in cloud storage popularity, more individuals are choosing to store large amounts of data on remote cloud service providers (CSPs) to save local storage resources. However, users’ primary worries revolve around maintaining data integrity and authenticity. Consequently, several cloud auditing methods have emerged to address these concerns. Many of these approaches rely on traditional public-key cryptography systems or are grounded in identity-based cryptography systems or certificateless cryptography systems. However, they are vulnerable to the increased costs linked with certificate management, key escrow, or the significant expenses of establishing a secure channel, respectively. To counter these limitations, Li et al. introduced a certificate-based cloud auditing protocol (LZ22), notable for its minimal tag generation overhead. Nonetheless, this protocol exhibits certain security vulnerabilities. In this paper, we devise a counterfeiting technique that allows the CSP to produce a counterfeit data block with an identical tag to the original one. Our counterfeiting method boasts a 100% success rate ∀ data block and operates with exceptional efficiency. The counterfeiting process for a single block of 10 kB, 50 kB, and 100 kB takes a maximum of 0.08 s, 0.51 s, and 1.04 s, respectively. By substituting the exponential component of homomorphic verifiable tags (HVTs) with non-public random elements, we formulate a secure certificate-based cloud auditing protocol. In comparison to the LZ22 protocol, the average tag generation overhead of our proposed protocol is reduced by 6.80%, 13.78%, and 8.66% for data sizes of 10 kB, 50 kB, and 100 kB, respectively. However, the auditing overhead of our proposed protocol shows an increase. The average overhead rises by 3.05%, 0.17%, and 0.45% over the LZ22 protocol’s overhead for data sizes of 10 kB, 50 kB, and 100 kB, correspondingly.

Linearly homomorphic signature (LHS) allows the acquisition of a new legal signature using the homomorphic operation of the original signatures. However, the public composability of LHS also prevents it from being used in some scenarios where the combiner needs to be designated. The LZZ22 scheme designates a combiner and preserves the signature structure by having the signer and the designated combiner share a secret. However, LZZ22 is not secure enough because the secret is constant. Here, we first prove that there is a polynomial time adversary that can crack the secret in LZZ22 through multiple signature queries. Then, we propose a new scheme, which realizes all the functions of LZZ22 and fixes the security problem by changing the secret with the message. The proposed scheme is shown to be secure against existential forgery on adaptively chosen subspace attacks under the random oracle model. Finally, we detail how to apply our scheme to the proxy signature and perform it on a personal computer, and the results show that our scheme is efficient.