Masami Mohri

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In cloud-computing services, using the SSL/TLS protocol is not enough to ensure data confidentiality. For instance, cloud service providers can see the plaintext after the decryption at the end point of a secure channel. It is wise to introduce an encryption layer between the service client and the communication channel so the data will not be seen by the(More)
Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is suitable for data access control on a cloud storage system. In CP-ABE, the data owner encrypts data under the access structure over attributes and a set of attributes assigned to users is embedded in user’s secret key. A user is able to decrypt if his attributes satisfy the ciphertext’s access(More)