| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve the problem of an attack that destroys synchronism between a tag and a server in an RFID system. <P>SOLUTION: A one-way hash function computing unit 318 converts a bit string into a bit string which is a hash value having a predetermined length. A comparison unit 320 compares the difference between two bit strings. A random number generating unit 342 generates random bit strings. An information storage unit 310 stores two different bit strings S and P, a bit string R, a bit string Ks which is a shared key with a bit string S radio tag, and a bit string TK which is a hash value generated in a radio tag on the basis of a shared key Kt. An update unit 344 replaces the S with a bit string which is a hash value in which a join bit string of the bit string S and the bit string R is generated as input, and substitutes the value of the bit string S before update into the bit string P. The comparison unit 320 compares a bit string TK' generated on the basis of the bit string Ks with the bit string TK, and if the both are matched, the update unit updates the bit string S and the bit string P. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
