초록 ▼

Mutual authentication is performed. A reader/writer (R/W) transmits to an IC card a code C.sub.1 that is a random number R.sub.A encrypted using a key K.sub.B. The IC card decrypts the code C.sub.1 into plain text M.sub.1 using the key K.sub.B. The IC card transmits to the R/W a code C.sub.2 that is

Mutual authentication is performed. A reader/writer (R/W) transmits to an IC card a code C.sub.1 that is a random number R.sub.A encrypted using a key K.sub.B. The IC card decrypts the code C.sub.1 into plain text M.sub.1 using the key K.sub.B. The IC card transmits to the R/W a code C.sub.2 that is the plain text M.sub.1 encrypted using a key K.sub.A and a code C.sub.3 that is a random number R.sub.B encrypted using the key K.sub.A. The R/W decrypts the codes C.sub.2 and C.sub.3 into plain text M.sub.2 and plain text M.sub.3, respectively, using the key K.sub.A. When the R/W determines that the plain text M.sub.2 and the random number R.sub.A are the same, it authenticates the IC card. Next, the R/W transmits to the IC card a code C.sub.4 that is the plain text M.sub.3 encrypted using the key K.sub.B. The IC card decrypts the code C.sub.4 into plain text M.sub.4 using the key K.sub.B. When the IC card determines that the plain text M.sub.4 and the random number R.sub.B are the same, it authenticates the R/W.

대표청구항 ▼

[ What is claimed is:] [1.] An authentication method between a first information processing apparatus and a second information processing apparatus, wherein said first information processing apparatus and said second information processing apparatus include storage means for storing a first key and

[ What is claimed is:] [1.] An authentication method between a first information processing apparatus and a second information processing apparatus, wherein said first information processing apparatus and said second information processing apparatus include storage means for storing a first key and a second key, encryption means for encrypting predetermined data using either one of said first key and said second key and decryption means for decrypting a code generated by either one of said second key and said first key, said method comprising the steps of:encrypting random first data into a first code using said first key of said encryption means of said first information processing apparatus;decrypting said first code into second data using said first key of said decryption means of said second information processing apparatus;encrypting said second data into a second code using said second key of said encryption means of said second information processing apparatus;encrypting random third data into a third code using said second key of said encryption means of said second information processing apparatus;decrypting said second code into fourth data using said second key of said decryption means of said first information processing apparatus;authenticating said second information processing apparatus by said first information processing apparatus on the basis of said first data and said fourth data;decrypting said third code into fifth data using said second key of said decryption means of said first information processing apparatus;encrypting said fifth data into a fourth code using said first key of said encryption means of said first information processing apparatus;decrypting said fourth code into sixth data using said first key of said decryption means of said second information processing apparatus; andauthenticating said first information processing apparatus by said second information processing apparatus on the basis of said third data and said sixth data.