A distribution system including, for connection over a network: a plurality of client upload devices, each client upload device storing one or more chunks of a content file; a client download device configured to download from the client upload devices chunks of the content file stored by the respective client upload devices; and an incentive device configured to generate token data packets exchangeable for chunks of the content file; wherein the client download device is configured to acquire a plurality of token data packets from the incentive device and to communicate with individual respective client upload devices and thereby download, in exchange for respective token data packets, stored chunks of the content file; each client upload device is configured to communicate with the client download device and, thereby, upload to the client download device stored chunks of the content file in exchange for token data packets acquired by the client download device from the incentive device and is configured to transmit to the incentive device token data packets received from the client download device; each client upload device is configured to upload to the client download device chunks of the content file in encrypted form; the client download device is configured so as, upon receipt of a chunk of the content file in encrypted form, to send to the client upload device from which the chunk of the content file was received a token data packet together with a request for a decryption key; each client upload device is configured so as, upon receipt of a token data packet and a request for a decryption key from the client download device, to send to the client download device the decryption key for decrypting the encrypted chunk of the content file; and the client download device is configured so as, upon receipt of a decryption key from a client upload device, to decrypt the respective chunk of the content file and to send to the incentive device the decryption key thereby identifying to the incentive device the respective chunk and the client upload device from which the respective chunk was received. a plurality of client upload devices, each client upload device storing one or more chunks of a content file; a client download device configured to download from the client upload devices chunks of the content file stored by the respective client upload devices; and an incentive device configured to generate token data packets exchangeable for chunks of the content file; wherein the client download device is configured to acquire a plurality of token data packets from the incentive device and to communicate with individual respective client upload devices and thereby download, in exchange for respective token data packets, stored chunks of the content file; each client upload device is configured to communicate with the client download device and, thereby, upload to the client download device stored chunks of the content file in exchange for token data packets acquired by the client download device from the incentive device and is configured to transmit to the incentive device token data packets received from the client download device; each client upload device is configured to upload to the client download device chunks of the content file in encrypted form; the client download device is configured so as, upon receipt of a chunk of the content file in encrypted form, to send to the client upload device from which the chunk of the content file was received a token data packet together with a request for a decryption key; each client upload device is configured so as, upon receipt of a token data packet and a request for a decryption key from the client download device, to send to the client download device the decryption key for decrypting the encrypted chunk of the content file; and the client download device is configured so as, upon receipt of a decryption key from a client upload device, to decrypt the respective chunk of the content file and to send to the incentive device the decryption key thereby identifying to the incentive device the respective chunk and the client upload device from which the respective chunk was received.