In December of 2010 NIST selected five SHA-3 finalists - BLAKE, Grcstl, JH, Keccak, and Skein to advance to the third （and final） round of the SHA-3 competition. At present most specialists and scholars focus on the...In December of 2010 NIST selected five SHA-3 finalists - BLAKE, Grcstl, JH, Keccak, and Skein to advance to the third （and final） round of the SHA-3 competition. At present most specialists and scholars focus on the design and the attacks on these hash functions. However, it is very significant to study some properties of their primitives and underlying permutations. Because some properties reflect the pseudo-randomness of the structures. Moreover, they help us to find new cryptanalysis for some block cipher structures. In this paper, we analyze the resistance of JH and Grcstl-512 against structural properties built on integral distinguishers. And then 31.5 （out of 42） rounds integral distinguishers for JH compression function and 11.5 （out of 14） rounds for Grcstl-512 compression function are presented.展开更多
The cloud allows clients to store and share data.Depending on the user’s needs,it is imperative to design an effective access control plan to share the information only with approved users.The user loses control of t...The cloud allows clients to store and share data.Depending on the user’s needs,it is imperative to design an effective access control plan to share the information only with approved users.The user loses control of their data when the data is outsourced to the cloud.Therefore,access control mechanisms will become a significant challenging problem.The Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is an essential solution in which the user can control data access.CP-ABE encrypts the data under a limited access policy after the user sets some access policies.The user can decrypt the data if they satisfy the limited access policy.Although CP-ABE is an effective access control program,the privacy of the policy might be compromised by the attackers.Namely,the attackers can gather important information from plain text policy.To address this issue,the SHA-512 algorithm is presented to create a hash code for the user’s attributes in this paper.Depending on the created hash codes,an access policy will be formed.It leads to protecting the access policy against attacks.The effectiveness of the proposed scheme is assessed based on decryption time,private key generation time,ciphertext generation time,and data verification time.展开更多
Cloud computing is a kind of computing that depends on shared figuring assets instead of having nearby servers or individual gadgets to deal with applications. Technology is moving to the cloud more and more. It’s no...Cloud computing is a kind of computing that depends on shared figuring assets instead of having nearby servers or individual gadgets to deal with applications. Technology is moving to the cloud more and more. It’s not just a trend, the shift away from ancient package models to package as service has steadily gained momentum over the last ten years. Looking forward, the following decade of cloud computing guarantees significantly more approaches to work from anyplace, utilizing cell phones. Cloud computing focused on better performances, better scalability and resource consumption but it also has some security issue with the data stored in it. The proposed algorithm intents to come with some solutions that will reduce the security threats and ensure far better security to the data stored in cloud.展开更多
基金Supported by the National Natural Science Foundation of China (No. 60873259 and No. 60903212)Knowledge Innovation Project of the Chinese Academy of Sciences
文摘In December of 2010 NIST selected five SHA-3 finalists - BLAKE, Grcstl, JH, Keccak, and Skein to advance to the third （and final） round of the SHA-3 competition. At present most specialists and scholars focus on the design and the attacks on these hash functions. However, it is very significant to study some properties of their primitives and underlying permutations. Because some properties reflect the pseudo-randomness of the structures. Moreover, they help us to find new cryptanalysis for some block cipher structures. In this paper, we analyze the resistance of JH and Grcstl-512 against structural properties built on integral distinguishers. And then 31.5 （out of 42） rounds integral distinguishers for JH compression function and 11.5 （out of 14） rounds for Grcstl-512 compression function are presented.
文摘The cloud allows clients to store and share data.Depending on the user’s needs,it is imperative to design an effective access control plan to share the information only with approved users.The user loses control of their data when the data is outsourced to the cloud.Therefore,access control mechanisms will become a significant challenging problem.The Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is an essential solution in which the user can control data access.CP-ABE encrypts the data under a limited access policy after the user sets some access policies.The user can decrypt the data if they satisfy the limited access policy.Although CP-ABE is an effective access control program,the privacy of the policy might be compromised by the attackers.Namely,the attackers can gather important information from plain text policy.To address this issue,the SHA-512 algorithm is presented to create a hash code for the user’s attributes in this paper.Depending on the created hash codes,an access policy will be formed.It leads to protecting the access policy against attacks.The effectiveness of the proposed scheme is assessed based on decryption time,private key generation time,ciphertext generation time,and data verification time.
文摘Cloud computing is a kind of computing that depends on shared figuring assets instead of having nearby servers or individual gadgets to deal with applications. Technology is moving to the cloud more and more. It’s not just a trend, the shift away from ancient package models to package as service has steadily gained momentum over the last ten years. Looking forward, the following decade of cloud computing guarantees significantly more approaches to work from anyplace, utilizing cell phones. Cloud computing focused on better performances, better scalability and resource consumption but it also has some security issue with the data stored in it. The proposed algorithm intents to come with some solutions that will reduce the security threats and ensure far better security to the data stored in cloud.
