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, 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, 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 a decryption key using the read key information; decrypting the read first information using the generated decryption key; comparing the decrypted first information and predetermined second information; and performing 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, 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, 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 a decryption key using the read key information; decrypting the read first information using the generated decryption key; comparing the decrypted first information and predetermined second information; and performing a registration process for registering the communication apparatus, based on a result of the comparing, reading, 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 a decryption key using the read key information; decrypting the read first information using the generated decryption key; comparing the decrypted first information and predetermined second information; and performing 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.