An information processing method in an information processing system including a communication apparatus and an information processing apparatus , the communication apparatus including a first communication unit that performs communication via a predetermined wireless communication, the information processing apparatus including a second communication unit that performs communication via the predetermined wireless communication, wherein in the information processing method, the communication apparatus performs: writing (S701), in response to a user operation on the communication apparatus, key information to be used for generating a decryption key and predetermined first information that is stored in the communication apparatus and is encrypted by using an encryption key, into a storage area that the information processing apparatus is capable of referring to by using the second communication unit; the information processing apparatus performs: reading (S804), in response to a user operation on the information processing apparatus, by using the second communication unit, the key information and the first information that have been written into the storage area; generating (S807) a decryption key using the read key information; decrypting (S808) the read first information using the generated decryption key; comparing (S809) the decrypted first information and predetermined second information; and performing (S810) a registration process for registering the communication apparatus, based on a result of the comparing, characterized in that , regardless of communication with the communication apparatus, the predetermined second information is stored in the information processing apparatus in advance, and the registration process is performed based on a fact that the decrypted first information corresponds with the predetermined second information in the comparing. writing (S701), in response to a user operation on the communication apparatus, key information to be used for generating a decryption key and predetermined first information that is stored in the communication apparatus and is encrypted by using an encryption key, into a storage area that the information processing apparatus is capable of referring to by using the second communication unit; the information processing apparatus performs: reading (S804), in response to a user operation on the information processing apparatus, by using the second communication unit, the key information and the first information that have been written into the storage area; generating (S807) a decryption key using the read key information; decrypting (S808) the read first information using the generated decryption key; comparing (S809) the decrypted first information and predetermined second information; and performing (S810) a registration process for registering the communication apparatus, based on a result of the comparing, reading (S804), in response to a user operation on the information processing apparatus, by using the second communication unit, the key information and the first information that have been written into the storage area; generating (S807) a decryption key using the read key information; decrypting (S808) the read first information using the generated decryption key; comparing (S809) the decrypted first information and predetermined second information; and performing (S810) a registration process for registering the communication apparatus, based on a result of the comparing, characterized in that , regardless of communication with the communication apparatus, the predetermined second information is stored in the information processing apparatus in advance, and the registration process is performed based on a fact that the decrypted first information corresponds with the predetermined second information in the comparing. <EOS>