发明名称 |
DATA DECRYPTION DEVICE, ATTRIBUTE-BASED ENCRYPTION SYSTEM, RANDOM NUMBER ELEMENT REMOVING DEVICE, RANDOMIZED SECRET KEY GENERATION DEVICE, DATA DECRYPTION METHOD, AND DATA DECRYPTION PROGRAM |
摘要 |
A device and method enhancing security of encrypted data by dividing a decrypting process of an attribute-based encryption scheme into plural stages. A KEM key partly decrypting part generates an r-KEM key mask value including a random number element, by performing a decrypting process for an encrypted KEM key being a common key encrypted using an attribute conditional expression, using an r-user secret key obtained by including the random number element into a user secret key generated in accordance with the attribute-based encryption scheme. A random number element removal requesting part requests an IC card to remove the random number element from the r-KEM key mask value, and acquires a KEM key mask value from the IC card. A mask removing part generates a KEM key using the KEM key mask value. A data decrypting part decrypts an encrypted data main body into target data using the KEM key. |
申请公布号 |
US2015278553(A1) |
申请公布日期 |
2015.10.01 |
申请号 |
US201314433476 |
申请日期 |
2013.11.01 |
申请人 |
MITSUBISHI ELECTRIC CORPORATION |
发明人 |
Matsuda Nori;Hattori Mitsuhiro;Ichikawa Sachihiro;Ito Takashi;Hirano Takato |
分类号 |
G06F21/72;H04L9/08 |
主分类号 |
G06F21/72 |
代理机构 |
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代理人 |
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主权项 |
1. A data decryption device comprising:
a common key partly decrypting circuit that generates a randomized mask common key including a random number element, by performing a decrypting process for an encrypted common key being a common key encrypted using an attribute conditional expression including an attribute value, using a randomized secret key which is obtained by including the random number element into a user secret key generated in accordance with an attribute-based encryption scheme using the attribute value representing an attribute; a mask common key acquiring circuit that acquires a mask common key which is obtained by removing the random number element from the randomized mask common key generated by the common key partly decrypting circuit; a mask removing circuit that generates the common key using the mask common key acquired by the mask common key acquiring circuit; and a data decrypting circuit that decrypts target data having been encrypted using the common key, using the common key generated by the mask removing circuit. |
地址 |
Chiyoda-ku, Tokyo JP |