A method of encrypting communication between a server and a peripheral device sent through a control device, comprising: at the server having one or more processors and memory storing one or more programs to be executed by the one or more processors: receiving a device registration request from the peripheral device via the control device, the device registration request including a predetermined device ID of the peripheral device and a user identifier associated with the control device; and in response to the device registration request: associating the predetermined device ID with the user identifier; and processing the device registration request as a session request requesting a session key for encrypting communication between the peripheral device and the server sent through the control device; in response to the session request, generating a first session key for encrypting and decrypting future communication between the peripheral device and the server sent through the control device; in accordance with the predetermined device ID, identifying a pre-stored encryption key corresponding to the predetermined device ID from a database of the server, wherein the pre-stored encryption key is pre-stored in the peripheral device and the database of the server by a user or a manufacturer of the peripheral device; encrypting the first session key using the pre-stored encryption key; sending the encrypted first session key to the peripheral device via the control device, wherein the encrypted first session key is configured to be decrypted by the peripheral device using the pre-stored encryption key; and encrypting and decrypting communication between the server and the peripheral device sent through the control device using the first session key (607, 608), wherein the control device does not possess the first session key. at the server having one or more processors and memory storing one or more programs to be executed by the one or more processors: receiving a device registration request from the peripheral device via the control device, the device registration request including a predetermined device ID of the peripheral device and a user identifier associated with the control device; and in response to the device registration request: associating the predetermined device ID with the user identifier; and processing the device registration request as a session request requesting a session key for encrypting communication between the peripheral device and the server sent through the control device; receiving a device registration request from the peripheral device via the control device, the device registration request including a predetermined device ID of the peripheral device and a user identifier associated with the control device; and in response to the device registration request: associating the predetermined device ID with the user identifier; and processing the device registration request as a session request requesting a session key for encrypting communication between the peripheral device and the server sent through the control device; associating the predetermined device ID with the user identifier; and processing the device registration request as a session request requesting a session key for encrypting communication between the peripheral device and the server sent through the control device; in response to the session request, generating a first session key for encrypting and decrypting future communication between the peripheral device and the server sent through the control device; in accordance with the predetermined device ID, identifying a pre-stored encryption key corresponding to the predetermined device ID from a database of the server, wherein the pre-stored encryption key is pre-stored in the peripheral device and the database of the server by a user or a manufacturer of the peripheral device; encrypting the first session key using the pre-stored encryption key; sending the encrypted first session key to the peripheral device via the control device, wherein the encrypted first session key is configured to be decrypted by the peripheral device using the pre-stored encryption key; and encrypting and decrypting communication between the server and the peripheral device sent through the control device using the first session key (607, 608), wherein the control device does not possess the first session key.