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 such that a random number RA is 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 such that the plain text M1 is encrypted using a key KA and a code C3 such that a random number RB is 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 such that the plain text M3 is 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.