Opportunistic peer-to-peer synchronization in a synchronization system

A method for synchronizing data between client computing devices, the method comprising:

• for each client computing device available for peer-to-peer synchronization, advertising any domains on such client computing device that are available for synchronization, wherein such domains are advertised on a network to which the device is connected;
• in response to a client computing device (the “requesting device”) desiring to synchronize data from a domain, determining at such client computing device if there is a peer device available for peer-to-peer synchronization that is advertising the desired domain;
• in response to no peer device advertising the desired domain, attempting, at the requesting device, to establish a connection with a synchronization server to synchronize data from the desired domain with the server;
• in response to identifying a peer device advertising the desired domain (the “peer device”), sending a request from the requesting device to the peer device to establish a synchronization session;
• determining at the peer device whether or not the identity of the user associated with the requesting device can be verified;
• in response to the peer device being unable verify the user's identity, rejecting the request to establish a synchronization session;
• in response to the peer device verifying the user's identity and the validity of the request, establishing a synchronization session between the peer device and the requesting device, wherein, during the synchronization session, the requesting device and the peer device synchronize metadata for the desired domain;
• and
• in response to the requesting device requesting, during the synchronization session, a file or data object on the peer device that is associated with metadata to which the requesting device is authorized to access, sending the file/data object from the peer device to the requesting device.

A system for opportunistic peer-to-peer synchronization, comprising:

• a master synchronization server;
• a plurality of client devices that are configured to synchronize data with either a peer client device or the master synchronization server, wherein each client device is configured to:
• monitor synchronization information provided by one or more peer client devices to determine whether or not data that the client device desires to synchronize is available for synchronization with a peer client device:
• if a peer client device is available for synchronizing such data, synchronize such data with the peer client device;
• if no peer client device is available for synchronizing such data, synchronize such data with the master synchronization server until a peer client device is available for synchronizing such data;
• and
• switch between synchronizing between a peer device and a master synchronization server is a synchronization session is interrupted.