Patent ID: 8565583

Claim:
A content transmission/reception system that includes a content transmission device and a content reception device, the content transmission device comprising: a storage unit operable to store therein an edited content composed of a partial original content and a partial edited content, the partial original content being a part of an original content, the partial edited content being a part obtained by editing a part of the original content; a division unit operable to divide each of the partial original content and the partial edited content to generate a plurality of pieces of transfer data; an encryption unit operable to generate a nonce value with respect to each of the pieces of transfer data, such that (i) discontinuity exists between a nonce value generated with respect to one of the pieces of transfer data and a nonce value that has been immediately previously generated, the one piece of transfer data being generated immediately after a switch between the partial original content and the partial edited content, and (ii) continuity exists between a nonce value generated with respect to each of the pieces of transfer data excepting the one piece of transfer data and a nonce value that has been immediately previously generated, generate a key based on each of the generated nonce values, and encrypt a corresponding one of the pieces of transfer data with use of the generated key, thereby to obtain a plurality of pieces of encrypted transfer data; and a transmission unit operable to transmit the pieces of encrypted transfer data together with the respective nonce values in order of generation of the pieces of encrypted transfer data, and the content reception device comprising: a reception unit operable to sequentially receive, as a content, the pieces of encrypted transfer data together with the respective nonce values; a decryption unit operable to generate a key based on each of the received nonce values, and decrypt a corresponding one of the received pieces of encrypted transfer data with use of the generated key, thereby to obtain a plurality of pieces of transfer data; a judgment unit operable to judge, with respect to each of the received nonce values, whether continuity or discontinuity exists between the received nonce value and a nonce value that has been immediately previously received; and a writing unit operable to sequentially write, as the content, the obtained pieces of transfer data into a recording medium, and when the judgment unit judges that discontinuity exists therebetween, write, into the recording medium, information indicating that the received content contains a partial edited content.