| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an encryption technique which is capable of shortening a bit length of a key and of easily achieving a high security without preparing a huge prime number. <P>SOLUTION: An encryption device includes: key curve storage means where a plurality of key curves H<SB POS="POST">k</SB>of space-filling curves in an N-dimensional space are stored; key number exchanging means which exchanges a key number K with a decryption device; message point generation means which maps a message code to the N-dimensional space to generate a message point Y; and encrypted code generation means which, when an injective function which maps a point A in the N-dimensional space to an ordinal number i<SB POS="POST">A</SB>in a one-dimensional ordinal space by a key curve H<SB POS="POST">K</SB>is denoted as L<SB POS="POST">K</SB>(A) and its inverse function is denoted as L<SB POS="POST">K</SB><SP POS="POST">-1</SP>(i<SB POS="POST">A</SB>), uses an encode function f<SB POS="POST">e</SB>on the basis of the point Y to calculate a point V in accordance with V=L<SB POS="POST">K</SB><SP POS="POST">-1</SP>[f<SB POS="POST">e</SB>(L<SB POS="POST">K</SB>(Y))]. The decryption device includes key curve storage means, key number exchanging means, and decrypting operation means which calculates the message point Y in accordance with Y=L<SB POS="POST">K</SB><SP POS="POST">-1</SP>[f<SB POS="POST">e</SB><SP POS="POST">-1</SP>(L<SB POS="POST">K</SB>(V))] on the basis of the point V. <P>COPYRIGHT: (C)2012,JPO&INPIT |
