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SM4 national security algorithm has been widely used in data encryption and decryption, However, with the explosive growth of the data volume of the Internet, there are problems such as the slow speed and high CPU utilization of the SM4 algorithm running in pure software mode, while the field programmable gate array or dedicated integrated circuit based on Verilog/VHDL has problems such as poor flexibility and difficulty in upgrading and maintenance. In order to solve the above problems, a design scheme of heterogeneous reconfigurable computing system based on SM4algorithm is proposed. Using high-level synthesis and heterogeneous reconfigurable technology, the customized computing architecture of SM4 algorithm’s electronic cipher book mode and counter mode is designed by optimizing the allocation and transmission of data memory, optimizing the loop, vectorizing the kernel and adding computing units, and the system is deployed on the FPGA heterogeneous platform. The experimental results show that the customized computing architecture of SM4-ECB and SM4-CTR, two mainstream operating modes, on the Intel Stratix 10 GX2800,has a throughput of 109.48Gbps and 63.73Gbps respectively, which is 232.63 times and 141.62 times the throughput of the corresponding mode on the Intel Xeon E5-2650 V2 CPU. The performance of the whole heterogeneous reconfigurable computing system composed of this core module, including data input, encryption and decryption, and output, has also reached 4.90 times and 3.56 times of that of pure software mode. This paper not only realizes customized acceleration for specific modes, but also flexibly supports different computing modes through hardware reconfiguration, taking into account the flexibility and efficiency of the system. [ABSTRACT FROM AUTHOR]

In view of the security risks faced by RAM(Random Access Memory) and Flash memory of embedded on-chip systems, this study outlines physical attacks against memory of traditional SoC(System on Chip) chips, and presents a memory controller that supports encryption algorithms. Using the lightweight block cipher algorithm LBlock-s, the cryptographic security analysis shows that the algorithm has a good resistance to differential cryptanalysis. Compared with traditional block cipher algorithms such as AES(Advanced Encryption Standard), the proposed method reduces hardware resource consumption while guaranteeing security and is suitable for all kinds of resource-constrained secure SoC chips. To improve the data throughput, the hardware structure of the algorithm is expanded so that the standard 32 rounds of encryption or decryption take 1 clock cycle. This scheme guarantees that sensitive data cannot be parsed even if acquired by the attacker without consuming more hardware resources and encrypting delay, and effectively avoids physical attack on the security chip. [ABSTRACT FROM AUTHOR]

In view of the security problem of embedded device firmware update, this study proposes a multi-check firmware security update scheme based on hash, symmetric and asymmetric encryption algorithms. In this study, the master key pairs, temporary key pairs, shared key and hash chain are designed to protect firmware update from identity authentication, data encryption, integrity check and other aspects, which can effectively prevent illegal users, firmware tampering, firmware data leakage, replay attack, firmware rollback and other attacks. In this study, the concrete implementation of the security update scheme is carried out. The experiment results show that compared with the ISP(In System Programming) and IAP(In Application Pragramming) technologies without any security protection, the scheme achieves the security protection of the whole process of firmware update at the time cost of about 7% and 11%, it provides a safe and reliable update method for embedded device firmware update. [ABSTRACT FROM AUTHOR]

Agricultural product supply chain and blockchain are closely integrated with the continuous acceleration of agricultural modernization. The clustered supply chain has gradually developed from a single supply chain in recent years. There is heat competition among peer enterprises in the clustered agricultural product supply chain blockchain. Among them, the data on the blockchain is publicly available to all participants. The private data on the chain has been adopted as an encrypted storage model, in order to protect users' privacy. The existing single-department supervision scheme is unsuitable for the complex cluster agricultural supply chain. The multi-sector supervision can be expected to serve as a promising way in the current reality. However, multi-department supervision is still challenging to ensure the sharing of encrypted data on the chain without redundant information for irrelevant departments. It is a high demand to improve supervision efficiency and credibility. Fortunately, the ciphertext-policy attribute-based encryption (CP-ABE) can be a one-to-numerous encryption, essentially a public key encryption system. The CP-ABE can realize the sharing of data for the users with specified attributes suitable for the application environment of multi-department supervision of the blockchain in the clustered agricultural supply chain. In this research, a multi-department supervision scheme was proposed in the verifiable blockchain ciphertext policy for the cluster agricultural supply chains using CP-ABE. A chain of custody was set up outside the business chain, including the supervisors from various departments to facilitate the management of supervisors. The chain of custody managed data on the business chain through “cross-chain governance.” Different supervision strategies were set for the data on the chain, according to the data type. The administrator of the supervision department was set as the department's supervisor to supervise the specific data of the specific chain. According to the supervision strategy on the chain, the enterprise users encrypted the data using CP-ABE to realize the disclosure of data for privacy. A CP-ABE-based access tree verification scheme was designed to combine the smart contracts and supervision strategies, and then to verify the CP-ABE access tree before the data was uploaded to the chain, in order to ensure that the data was available to the designated supervisor. The direct use of CP-ABE was inefficient for data encryption. Therefore, hybrid encryption was used to encrypt and share the data. The specific implementation was to encrypt the original data with symmetric encryption and then use the CP-ABE to encrypt the symmetric encryption key. A supervision prototype system was constructed under the blockchain ciphertext of the clustered agricultural supply chain using Hyperledger Fabric. The system was tested in two aspects of function and performance. The functional test showed that the system fully met the needs of essential multi-department supervision. The performance test showed that each time the number of supervisors in the supervision strategy increased by 10, while the average on-chain time was extended by about 500 ms, and the average throughput was 438 (number of transactions/s, transactions/s). When the number of supervisors for a single data type of a single enterprise was within a reasonable range, the clustered system was adept to the multi-department supervision under the condition of the primary clustered agricultural supply chain blockchain ciphertext-application requirements. Security analysis indicated the high-security system. As such, this scheme can be expected suitable for the multi-departmental, specialized, and fine-grained supervision of data on the blockchain under data encryption. The pressure of regulators can be inspired by the development of blockchain supervision of cluster agricultural supply chains. [ABSTRACT FROM AUTHOR]

In the modern medical field of pathological diagnosis and surgical practice, it is necessary to perform three-dimensional reconstruction of CT (computed tomography) to realize three-dimensional visualization of two-dimensional images to improve the accuracy of diagnosis and operation. To address the current problems of time-consuming and poor accuracy of 3 D reconstruction, this paper proposed an improved MC (marching cubes) algorithm, which used an enclosing box segmentation algorithm to extract voxels containing equivalent surfaces, effectively improving the reconstruction efficiency, calculated the intersection of equivalent surfaces and voxels by using trilinear interpolation, thus improving the reconstruction accuracy. In order to ensure the security of medical information in cloud storage and network transmission, this paper proposed a three-dimensional model encryption scheme based on fractional Lorenz chaos, which realized the chaotic encryption of reconstruction data in the frequency domain. The experimental results show that the improved MC algorithm has good reconstruction efficiency and reconstruction accuracy, and the proposed encryption scheme can effectively protect the reconstructed 3 D data and resist exhaustive attacks, differential attacks and statistical attacks. [ABSTRACT FROM AUTHOR]

Objectives: Security of vector spatial data is of importance in the community of geographic information sciences. It is necessary to encrypt the vector spatial data based on the consideration of data security. The existing method is to encrypt the entire data file, which affects the view of attribute data and destroys vector spatial data structure. Methods: A coordinate encryption method which does not change the structure of vector spatial data file is proposed, which not only protects the security of data, but also has no impact on the normal use of data. Firstly, vector spatial data are encrypted in Haar transform domain by the secret key. The secret key used to encrypt the coordinate data is generated combined Hash key with Gaussian random number. The average coefficient and the differential coefficient are obtained from Haar transformation of the vertex sequence of vector spatial data and are encrypted by the secret key. After that, the encrypted coordinates are obtained by Haar inverse transformation of data. Finally, the Gaussian random number is utilized to scramble the vertex sequence in order to get the encrypted disordered vector spatial data. Results: The experimental results show that: (1)The structure and attribute data of the vector spatial data file are completely unchanged after encryption, only the coordinates are encrypted, and efficiency is improved. (2) The algorithm can effectively decrypt and restore the original vector spatial data, with high security. Conclusions: The proposed method can not change the structure of vector spatial data, and the efficiency of encryption is improved. [ABSTRACT FROM AUTHOR]

The increase of in-vehicle electronic equipment makes the in-vehicle network face more and more threats. The lack of authentication of the Electronic Control Unit in the in-vehicle network and the lack of encryption of the communication data of the Controller Area Network make the in-vehicle network vulnerable to replay, ECU injection, man-in-the-middle forged messages, eavesdropping, etc, Witch make serious consequences. Aiming at the current vehicle network threats, a vehicle network security communication model based on SecOC is proposed. This model uses the SM4 cryptographic algorithm and the improved key management based on Bkake2 s to realize the authentication of the vehicle ECU and the encryption and authentication of the vehicle network message. Finally, after analysis and testing, the model can protect the invehicle network security and be more efficient. [ABSTRACT FROM AUTHOR]

With the development of big data and the increase of encryption scenarios, it 's difficult to meet the requirements of encryption performance with only software-run encryption methods, and FPGA/ ASIC encryption systems implemented using Verilog/VHDL methods have poor flexibility and difficult maintenance and upgrades problem. In response to the above problems, this paper designed and implemented an AES algorithm encryption system based on heterogeneous reconfigurable computing, including three mainstream modes of AES algorithm ECB, CBC, CTR, each mode realized 128 bit, 192 bit, 256 bit encryption of three key sizes. This paper realized the hardware acceleration of the module based on FPGA, and realized the dynamic switching of different modes and different bit width encryption modules based on the hardware reconfigurable mechanism. By implementing and verifying the system on Intel Stratix 10, the experimental results show that the throughput rates of AES-ECB, AES-CTR and AES-CBC in the system are 116.43 Gbps,60. 34 Gbps, and 4. 32 Gbps, respectively. The ECB mode compared with Intel Xeon E5-2650 V2 CPU and NVIDIA GeForce GTX 1080 GPU achieves 23.18 times and 1.43 times acceleration ratios respectively. Compared with the method just calling the CPU,the overall system has a computational acceleration ratio of 4.72. [ABSTRACT FROM AUTHOR]

To solve both problems of data leakage and sharing difficulties in the method of centralized storage of traditional electronic forest fire archival data, this paper puts forward a sharing scheme for forest fire archival data based on block chain technology. Combining block chain technology and interplanetary file system（IPFS）, the scheme establishes a block chain network based on the Hyperledger Fabric platform, uploads complete forest fire archival data to the network of IPFS after symmetrical encryption and generated data summary information to the block chain network after asymmetric encryption, and adopts proxy re-encryption algorithm to encrypt the generated information in order to ensure data security in the process of data communication. The results of encryption tests show that the symmetric encryption algorithm can encrypt 20 M fire data 59.3 ms faster than do the asymmetric encryption algorithm; according to the data of data storage tests, it can be found that it takes 4.117 5 ms to upload 20 M fire data to the network of IPFS. The results of system performance tests show that the sharing scheme for forest fire archival data based on block chain technology has a query ceiling of 300 TPS for such data. On the premise of ensuring the efficiency of system, the scheme can realize the immutable storage of forest fire data and the purpose to expand the sharing scope of such data through the increase of nodes in the network. [ABSTRACT FROM AUTHOR]

With the growth of the breadth and depth of LoRa network applications, the demand for information security is gradually increasing, so ensuring the security of data transmission network is a necessary condition for the development and application of LoRa network. The traditional LoRa net work has its own encryption mechanism in the process of data transmission, which uses AES-128 encryption algorithm to encrypt data messages. However, in the process of encryption and decryption, the two keys are relatively symmetric, so that their parameters are roughly the same. When any one of the keys is leaked, it is easy to calculate the other key. In view of the existing security problems, a hybrid data encryption scheme is proposed： RSA asymmetric encryption algorithm is introduced into LoRa network, and the key used in the process of encryption and decryption of data by AES encryption algorithm is encrypted by taking advantage of RSA encryption algorithm's high security, so as to reduce the security risks of network data transmission and improve the security. Then, on this basis, AES and RSA encryption algorithm are optimized to ensure the efficiency of data transmission. Finally, the design is tested. The test results show that the proposed method can not only ensure the efficiency of data transmission, but also enhance the security of key against stealing, thus greatly improving the security of data transmission in LoRa network. [ABSTRACT FROM AUTHOR]

In order to effectively solve the problems of multimedia data security and copyright protection in the process of transmission and storage, this paper proposed a commutative encryption and watermarking algorithm based on Zu Chongzhi(ZUC) stream cipher algorithm and DWT-SVD. Based on the invariance of the singular value, the algorithm embedded the watermark into the singular value, and used the ZUC algorithm to permutate and encrypt the set of the singular value matrix and the set of the singular matrix respectively. The sequence of embedding operation and encryption operation did not affect the generation of the watermarked ciphertext, meanwhile, both watermarked ciphertext and decrypted plaintext can extract watermark completely. The experimental results show that the watermark has good invisibility, and the algorithm has high security and a certain robustness. [ABSTRACT FROM AUTHOR]

Commutative encryption and watermarking ( CEW) is a combination of cryptographic and digital watermarking technology, which is used for multimedia information security and copyright protection. In order to ensure the security of carrier data, this paper proposed an exchange encryption watermarking algorithm based on ZUC. The algorithm used the ZUC sequence cipher to generate the key and used modular operation to encrypt the carrier information. The sequence of watermark embedding operation and data encryption operation did not affect the generation of watermark ciphertext data. When extracting the watermark, the algorithm could realize the exchange of password operation and watermark operation. The experimental results show that the watermark extraction in ciphertext domain is consistent with that in plaintext domain, the image containing watermark is of high quality, the efficiency of encryption and decryption, watermark embedding and extraction are higher, and the algorithm has a certain robustness. [ABSTRACT FROM AUTHOR]

In order to solve the weakness of existing medial image encryption algorithm based on chaotic system in considering the image' s texture feature, this paper proposed a medical image encryption and decryption method based on chaotic mapping and adaptive partitioning. Firstly, it used the 2D Sine Logistic chaotic system to generate two secure sequences with good chaotic characteristics . Then, it divided the original medical image into fixed size image blocks, and calculated their maximum pixel difference and variance . According to the given threshold, it divided these image blocks into texture smooth blocks and texture complex blocks. Finally, it used the first chaotic sequence with ciphertext feedback mechanism to encrypt the smooth blocks, and encrypt the complex blocks by using the second chaotic sequence with plaintext feedback mechanism. Therefore, it obtained the encrypted image. Because the presented algorithm efficiently considered the texture characteristics of image blocks and optimized the algorithm of chaotic encryption, it improved the encryption and decryption efficiency of medical images. Experimental simulation results show that the presented algorithm has high security and encryption efficiency. Compared with the existent method, it reduces the encryption and decryption time by about 0. 5 times . The presented algorithm is suitable for real-time medical images encryption and decryption with big data size. [ABSTRACT FROM AUTHOR]

Aiming at the shortage of medical images encryption algorithm in efficiency and security, this paper proposed a novel medical image encryption algorithm in frequent domain based on 2D sine Logistic chaotic mapping. Firstly, the proposed algorithm used the integer wavelet transform of LeGall5/3 to transform medical image from frequent domain to spatial domain. In this way, the high correlation among pixels has disappeared. Then, the proposed algorithm utilized 2D sine logistic chaotic mapping to generate the chaotic sequences. In order to improve the encryption efficiency, this algorithm chose the low frequency coefficients of three-level decomposed to encrypt with chaotic diffusion and scrambling mechanism. In the same time, this algorithm also selected the medium-high frequency coefficients of two-level decomposed to encrypt by chaotic diffusion mechanism for solving the problem of obvious outline in encrypted image. Finally, this algorithm transformed the encrypted wavelet coefficients by the inverse integer wavelet transform and obtained the encrypted image. Experimental simulation results demonstrate that the proposed algorithm is able to protect medical images with low time complexity and a high security level. Compared with the existing spatial method, it reduces the encryption time by about 0.025 times. In addition, the proposed algorithm has better image imperceptibility as well as an excellent encryption efficiency compared to the existing frequent method. [ABSTRACT FROM AUTHOR]

In the traditional attribute-based encryption scheme, there are problems that the attributes contained in the access policy may leak sensitive information of the user and the malicious user leaks the private key to gain illegal profits without being blamed. At the same time, with the increasing of the number of attributes the length of the private key, ciphertext, and the decryption operation will increase and it bring greater communication overhead and computational overhead. To solve these problems, this paper proposed an attribute-based encryption scheme that can track keys and hide the access structure. The scheme improved the security of the encryption algorithm without affecting the efficiency of encryption and decryption. The scheme adopted a two -factor authentication mechanism to achieve more secure and efficient access control, and it used a secure signature mechanism for supporting traceable keys to track malicious users. Finally, the theoretical analysis show that this scheme proved to be safe under the standard model based on the DBDH hypothesis. [ABSTRACT FROM AUTHOR]

In order to solve the shortcomings of the traditional serial encryption method in single machine mode, such as the low density of data security, the difficulty in encrypting-efficiency to meet the requirement of increasing information data encryption and the excessive amount of memory in the running process, and so on. This paper designed a scheme of chaotic encryption algorithm based on Hadoop platform. The scheme used MapReduce parallel framework, chaotic encryption pseudorandom number and the principle of initial value sensitivity. And it proposed parallel chaotic encryption scheme for MapReduce framework and chaotic encryption optimization. It used the length of the plaintext as the initial value, and used Chen, Lorenz, Rossler chaotic system to generate secret key. At the same time, the paper proposed an idea of dividing plaintext data into blocks according to 1 MB. According to the offset, it judged each block to gene rate three key sequences of Chenn Lorenzi R0ssler whose length is 1 MB, to improve the security of data density, and reduce the amount of running memory and other purposes. This design framework used Chen sequence for plaintext messing operation, used Lorenz sequence for XOR diffusion ope ration and used Rössler sequence for modular auxiliary diffusion operation. Experiments prove that, for MapReduce, the optimization algorithm of using parallel framework and chaotic system can effectively reduce the amount of memory and improve the encryption speed, and the encryption ope ration associated with plaintext achieves the purpose of effectively defending against the attack of selected plaintext. [ABSTRACT FROM AUTHOR]

The problem of leaking through express sheet brings security risks to individuals, but also restricts the rapid development of express enterprises. This paper studied the privacy protection of express sheet. By combining the identity based encryption system (BF-IBE), the idea of authority design and the two-dimensional code technology, this paper designed a block encryption scheme. The scheme used a new private key distribution protocol (IC protocol) to solve the key management problem. This paper applied the block encryption scheme to the domain of express privacy protection, and designed a new privacy express sheet and express business process. The results show that the IC protocol uses in the block encryption scheme needs no inverse operation, and the bilinear pairings can be effectively reduced and the key management can be carried out easily. The encryption and decryption efficiency of the block encryption scheme is similar to that of BF-IBE. Its security is based on the discrete logarithm problem on elliptic curves. It can be applied to express field, which can effectively protect the user’s privacy. It is also suitable for other areas with block encryption requirements. [ABSTRACT FROM AUTHOR]

The design of efficient and secure lattice-based post quantum key exchange protocols has certain practical and theoretical significance. This paper proposed a scheme used straight-forward transformation LWE encryption mechanism and a ciphertext compression technology. This was a passively secure and practical key exchange protocol. Frodo was a key exchange scheme based on LWE problem proposed by Bos et al. which used the error reconciliation mechanism proposed by Peikert. The main advantage of the scheme over Frodo was simplicity. Compared with Frodo. the communications traffic merely increased by only 1.09%. reduced the complexity of the scheme effectively. It proved scheme to be passive security. which could resist quantum computer attacks. Compared with existing key exchange protocol based on learning with error, this protocol is very competitive. [ABSTRACT FROM AUTHOR]

A searchable encryption scheme that specifically supports genetic data was proposed to protect users from privacy risks. The existing searchable encryption schemes only support keywords search， they cannot be applied to genetic data without keywords. So， a security index using cryptographic primitives such as suffix trees and pseudo-random functions was constructed to implement arbitrary substring searches for ciphertext genomic data. The safety proof indicated that the method satisfies the dynamic adaptive security， and the efficiency is evaluated by both theoretical analysis and real data. This scheme can perform efficient and safe arbitrary substring search on genomic data，protect data integrity and privacy and has broad application prospects in the environment of personalized medical popularization. [ABSTRACT FROM AUTHOR]

In order to achieve greater safety in RSA encryption algorithm in the data encryption process, this paper made some improvements based on in-depth analysis on the traditional RSA algorithm. It put forward a more secure method with changing traditional double primes into four primes in the traditional RSA algorithm and eliminating the requirement for transferring the product n of two random primes in public key on the basis of parameter substitution. Instead, this paper replaced the original parameter n to a new introduced parameter x. In order to boost the efficiency in the introduced algorithm, this paper used the CRT(Chinese remainder theorem) to expedite the exponentiation of large numbers. The results demonstrate the feasibility of the improved algorithm, and it provides a safer path for messages transmission through public key encryption. At the same time, this paper carried out a comparative analysis of encryption and decryption time among the improved algorithm and the traditional double primes and four primes RSA algorithms. The results show that the improved algorithm to a certain degree enhanced the encryption and decryption efficiency between the message sender and receiver. [ABSTRACT FROM AUTHOR]

This paper proposes a searchable encryption model for graph data to address the problem that most of the current searchable encryption schemes cannot deal with complex data structures. The algorithms and security models of the scheme are described. Taking the encryption index of matrix structure into account， the detailed description of the searchable encryption scheme for graph data that supports adjacency queries is presented. The scheme utilizes pseudo-random functions and pseudo-random permutations to protect the privacy of the graph data and the encrypted index. Real models and ideal models test the security of the scheme. Compared with traditional searchable encryption schemes， the proposed scheme has more flexible searching ability and higher efficiency， which promotes broader application under big data environment. [ABSTRACT FROM AUTHOR]

To improve efficiency and ensure security, a nonlinear mapping order preserving encryption scheme (nOPE) was proposed. By nonlinear mapping and nonlinear splitting, the data distribution and the data frequency were hidden. The system model of order preserving encryption with problem model and adversary model was introduced in cloud environment. The order preserving encryption scheme was proposed for the problem model, and the correctness was verified. The scheme security under the two kinds of attack of adversary model was analyzed, and the scheme efficiency was compared with those of other different order preserving schemes. The results show that the proposed scheme can resist statistical attack and realize IND-DNCPA with good security. The average encryption time per hundred thousand encrypted data is about 30 ms with good efficiency, and the scheme can be deployed and implemented in any programmable language with good programmability. [ABSTRACT FROM AUTHOR]

Timed-release encryption( TRE) is a cryptography that studies the problem of sending information into the future,it can solve many practical problems to construct a feasible and safe TRE. This paper proposed a scheme based on the research of indistinguishability obfuscation and TRE. This scheme encapsulated the sender’s encryption and receiver’s decryption by a circuit and obfuscated this circuit by an indistinguishability obfuscator. It could make great use of the time of obfuscators obfuscate circuits,simplified the scheme and improved the security of this scheme. Finally,this paper proves the correctness and security of this TRE scheme. [ABSTRACT FROM AUTHOR]

This paper used dynamic time warping( DTW) algorithm to align side channel signals in differential power analysis( DPA) attacks. Based on the principle of DTW algorithm which produced a warp path for recomposing signal traces pair,it proposed a flexible alignment method. The practical experiments based on simulated misalignment signals obtained from a microcontroller( AT89C52) which implemented the data encryption standard( DES) cipher in software and inserted the random time delays. As the results show,running DPA on misaligned traces requires a much larger trace set when misalignment is appreciably increased,in contrast,performing DPA on the traces modified by flexible alignment can make it very low-cost in terms of the number of traces that need to be processed. The result also confirms the effectiveness of method mentioned above. [ABSTRACT FROM AUTHOR]

In order to solve the problems of data redundancy and low delivery ratio in DSNC algorithm,this paper proposed a routing algorithm for DTN based on dynamic segmented network coding and transmission capacity control( NC-TCC). It used the AONT matrix to encode the data at the source node of the network to avoid redundant coding. At the intermediate nodes,it calculated the transfer capacity of opportunistic connection according to the mobile model of nodes. While the encoded packets did not exceed the transfer capacity it selected the data with higher priority for random coding. This method was easy to achieve the successful transmission of data. Simulation results show that the algorithm can effectively reduce the data redundancy and improve the efficiency of data transmission. [ABSTRACT FROM AUTHOR]

Aiming at the differential power attack of the encryption scheme based on lattice, Reparaz proposed an additively homomorphic R-LWE masking scheme in PQC 2016. This scheme could against the differential power attack effectively, but the additively homomorphic algorithm between the ciphertexts made the size of noise increase. It declined the rate of decryption correctness. In view of this problem, this paper proposed an improved R-LWE homomorphic masking scheme. By introducing the modular switching technology, it made a modular reduction with the cipher text of additively homomorphic. Under the premising that plaintext and the ciphertext were corresponding, it declined the size of noise in the ciphertext. And it could improve the decryption correctness of the scheme. In order to protect the sub keys, it introduced a random matrix to mask the sub key. And it made the correctness analysis and the safety proof. The proposed scheme has better security and efficiency compared to the original scheme. [ABSTRACT FROM AUTHOR]

As data communication and user privacy security problems during wireless body area network (WBAN) combining with the cloud computing, this paper proposed multi-valued and ambiguous scheme (MAS) to solve the WBAN cloud data security issues. Firstly, it introduced an overview of MAS algorithm with the encryption and reasoning processes. Then, it applied this algorithm to solve the WBAN cloud data security issues, and that the algorithm could effectively guarantee the security of data communication between the cloud and it proved the WBAN. In addition, combined with existing encryption algorithms, it achieved an example of this algorithm. Finally, testde the efficiency of the proposed method. The experimental results show that as the input data from 0 to 900 KB, the total time of encryption of this algorithm has been kept within 5 s, lower than DES’s and AES’s. The total time of decryption has been kept within 22, which are also lower than DES’s and AES’s. This indicates that proposed algorithm can be applied into settling the data security problem of WBAN. [ABSTRACT FROM AUTHOR]

Most of the traditional block cipher modes cannot be applied effectively on GPU. We study the traditional encryption models and put forward a packet encryption model cipher, called block random link encryption mode(RCBC),which is efficient, safe and meets parallel computing requirements. This model has a high efficiency, and increases the difficulty of decryption at the same time. Experimental results show that the proposed encryption algorithm has efficient processing ability on CPU_GPU. [ABSTRACT FROM AUTHOR]

AES is the mainstream encryption algorithm now. This paper studied that AES implementation had less area and high throughout rate. According to the characteristics of the substitution, S-box transformation used 16 x 16 pre-stored permutation table so that lookup efficiency space could be achieve 0(1). All the galois field elements 2 times were stored in a table the first. All of the computing needed only look-up table and addition. This was to avoid the finite field multiplication and effectively reduce the number of operations. Key expansion was independent of the encryption algorithm itself. It used positive edge of the clock to control key generation. It could send key at the falling edge of the same clock cycle. This could make the area optimized and achieve high throughput rate without waiting for the arrival of the next clock edge. It controlled the rounds of calling encryption function by counter. Each module could also be called multiple times so that the encryption chip area was reduced. Experiments show that the area of optimized AES occupies 11 163 Slices. It is decreased by 2 times compared to 20 173 Slices of original AES. [ABSTRACT FROM AUTHOR]

To synchronize image compression and encryption, on the basis of further research of MQ arithmetic encoder, this paper regarded the random sequence generated by Lorenz chaos system as flow key to modify context and decision which came into being in the process of bit plane coding of JPEG2000 compression algorithm. It changed the probability distribution of decision when MQ coding, which changed the output stream, and realized the image joint compression encryption in this way. It elaborated the rule of the context modification and the decision modification algorithm. The simulation results indicate that the proposed algorithm doesn't influence the compression efficiency compared with the original compression algorithm. What's more, it has high security and instantaneity. [ABSTRACT FROM AUTHOR]

To meet the watermarking requirement in encrypted domain, this paper proposed a novel reversible watermarking algorithm in histogram difference domain for encrypted image by utilizing a combination of histogram shifting and homomorphic encryption. It could embeded a watermark into the encrypted image directly to realize the process of plain image-encrypted image-watermark embedding, which simplified the traditional redundant process of plain image-encrypted image-decryption--watermark embedding-encryption again. Simulation experimental results demonstrate that the proposed algorithm can provide greater payload capacity and higher image fidelity. After it extracts the watermark completely, it can recover the original image reversibly. It outperforms other related algorithms. [ABSTRACT FROM AUTHOR]

Aiming at the problem of high complexity of image encryption algorithm at present, a new wavelet domain block encryption method was proposed. First, the algorithm decomposed the original image into multiple different resolution images using DWT(discrete wavelet transform), and the low-frequency coefficients of the image were scrambled by the hyperchaotic system. After IDWT(inverse discrete wavelet transform), bitwise XOR was performed on the reconstructured image with a sequence generated using hyperchaostic system. The experimental results verified that the grey information of the original image was hidden, this encrypting method had a large space of keys and high safety performance; and the scrambled image had good performance of the resisting statistic attack and differential cryptanalysis. [ABSTRACT FROM AUTHOR]

In order to improve the deficiencies of the existing scrambling algorithm effectively, a new image encryption algorithm based on dual scrambling about pixel position scrambling and RGB color space intensity value was proposed. Firstly, the rows and columns of 2D matrix would be mapped into ID vector by making use of new proposed scrambling method based on pixel position. Then a set of pseudo sequence was generated by using the Logistic mapping, and it was ranked from small to large. The position that corresponding to each element was recorded by group sequence, which was called key stream. Finally, the corresponding pixel position of ID vector was scrambled by index value which was formed by key stream. The encrypted image was obtained by ID vector rearranged into a new 2D matrix. The experimental results showed that the proposed method had a large key space, and the scrambled image had a histogram distribution of white noise. The correlation of image pixel values was smaller. It greatly improved the ability to resist the illegal attack and increased the safety of encrypted image. [ABSTRACT FROM AUTHOR]

Aiming at the security problem of chaos theory in cryptography application, a chaotic block encryption algorithm was designed based on the theory of discrete coupled map lattice and asymptotic deterministic randomness. The algorithm used aymptotic deterministic randomness key to diffuse the plaintext, and through the iteration of the discrete coupled map lattice the plaintext was encrypted. Then the validity, sensitivity and resistance of algorithm were tested and analyzed. The results showed that the security of chaotic encryption algorithm was higher. [ABSTRACT FROM AUTHOR]

The key encryption methods can't guarantee the key distribution security. To overcome the above limitations, this paper proposed an encryption scheme over fading channels based on independency of channel phase response. Firstly, the paper divided the channel between the sender and the eavesdropper into the cascade of the two channeled, and calculated the key security capacity. Secondly, the paper discussed the discrete source PSK encryption parameters. Finally, the legitimate users could guarantee the system security. Simulation results show that, the error rate is rapidly increased to 0.5 with the estimation error of the received signal phase is 0.001. [ABSTRACT FROM AUTHOR]

The large integer factorization is not only the most direct attacking method against RSA asymmetric encryption algorithm, but also the most important point to analyze the security of RSA. Study on the large integer factorization problem is of great value for theory and practice. TH paper summarized the study on of the large integer factorization problem and reviewed modern popular integer factorization algorithms, and introduced their basic principle and implementation steps. In addition, this paper made an analysis on existing large integer factorization techniques' advantage and disadvantage of implementation ad application. At last, this paper stated the future prospect of large integer factorization. [ABSTRACT FROM AUTHOR]

Aiming at the problem of security and privacy in RFID tag ownership transfer, particularly the owner's authorization recovery problem, a RFID tag ownership transfer protocol based on an optional model was proposed. The protocol used the reader's password to encrypt information, and strengthen the certificate protection of label information. After releasing the ownership, the original owner could choose whether to apply for reinstate authorization. If the application was successful, it could allow it to release the ownership after it finished the use of label information within the specified time to protect the security of privacy. The results showed that the protocol improved the security and flexibility of the tag ownership transfer, algorithm performance also had certain advantage. [ABSTRACT FROM AUTHOR]

In order to provide effective security protection for tenants' data in cloud computing applications, a third-party security tenant's data protection model is proposed to solve the security problems of cloud tenants data storage and retrieval. Data relationship hiding method is conducted in this model, that is to say the tenants' data is firstly sliced and then one-way function is employed to confuse the relationship between these different data slices. According to the demand for data privacy as well as the security grade definition, a data security grading scheme is further proposed, and the data storage security can be guaranteed by utilizing some encryption and anonymization on the data in sub-tables segmented by the security grading scheme. Combining with private information retrieval method, a keyword retrieval algorithm on the encrypted data is also proposed to protect the cloud data demand privacy security from tenants. The experimental results show the proposed model can well meet the security requirements of tenants' data storage and retrieval in cloud. [ABSTRACT FROM AUTHOR]

To prevent the leakage risk of traditional formula, the paper presents a new planning and design of formulation confidentiality management system. The system is based on the design concept of the business process reengineering ( BPR), used in the design of the composite encryption mode, i. e., the technology of two-dimensional bar code and MD5 encryption algorithm. The double encryption algorithms achieve a safety management system and is easy to use. It is proved that the system can protect the confidentiality of formula, and improve the efficiency of management. It has great practical application value. [ABSTRACT FROM AUTHOR]

Using RSA encryption algorithm and symmetric encryption algorithm, the hierarchical encryption algorithm for different levels of information of digital library was proposed. In this algorithm, the core information (first level information) was encrypted and decrypted using RSA, and the inside information (second level information) was encrypted and decrypted using RSA and symmetric algorithm. The first level manager could decrypt the first level information and the second level information, but the second level manager could only decrypt the second level information. None but the first level manager or the second level manager could decrypt. This kind of hierarchical management could not only satisfy the security requirements for different users of digital library, but also facilitate the hierarchical management of different levels of information for digital library. The hierarchical encryption scheme had the availability and effectiveness. [ABSTRACT FROM AUTHOR]