公开(公告)号：US20160240108A1

公开(公告)日：2016-08-18

申请号：US15027602

申请日：2014-06-16

Applicant: NEC CORPORATION

Inventor： Jun FURUKAWA

IPC: G09C1/00 ,  H04L9/08 ,  H04L9/06

CPC classification number: G09C1/00 ,  H04L9/0618

Abstract: An apparatus of this invention is directed to a ciphertext generation apparatus that can compare the magnitudes of encrypted numerical values and largely reduce the risk of information leakage while maintaining the confidentiality. This ciphertext generation apparatus includes a derived key generator that generates a derived key based on a main key and a document, an auxiliary derived key generator that generates an auxiliary derived key based on the main key, the document, and the derived key, an identifier-specific ciphertext generator that generates, based on an identifier of the document, the derived key, and the auxiliary derived key, an identifier-specific ciphertext in which the identifier is encrypted, and a relative value ciphertext generator that generates, based on the identifier and the derived key, a relative value ciphertext in which a relative value generated from the main key, the document, and the derived key is encrypted. A character string including the identifier-specific ciphertext and the relative value ciphertext is generated as a ciphertext for the document.

Abstract translation: 本发明的装置涉及一种密文生成装置，其可以比较加密数值的大小，并且在保持机密性的同时大大降低信息泄漏的风险。 该密文生成装置包括基于主密钥和文档生成导出密钥的导出密钥生成器，基于主密钥，文档和导出密钥生成辅助导出密钥的辅助导出密钥生成器，识别符 基于所述文档的标识符生成所述导出密钥和所述辅助导出密钥的特定密文生成器，其中标识符被加密的标识符特定密文，以及相对值密文生成器，其基于所述标识符 和派生密钥，其中从主密钥，文档和导出密钥生成的相对值被加密的相对值密文。 生成包含特定于标识符的密文和相对值密文的字符串作为文档的密文。