Authentication method, communication method, and information processing apparatus

摘要

Mutual authentication is performed. A reader/writer (R/W) transmits to an IC card a code C1 that is a random number RA encrypted using a key KB. The IC card decrypts the code C1 into plain text M1 using the key KB. The IC card transmits to the R/W a code C2 that is the plain text M1 encrypted using a key KA and a code C3 that is a random number RB encrypted using the key KA. The R/W decrypts the codes C2 and C3 into plain text M2 and plain text M3, respectively, using the key KA. When the R/W determines that the plain text M2 and the random number RA are the same, it authenticates the IC card. Next, the R/W transmits to the IC card a code C4 that is the plain text M3 encrypted using the key KB. The IC card decrypts the code C4 into plain text M4 using the key KB. When the IC card determines that the plain text M4 and the random number RB are the same, it authenticates the R/W.