Browse Prior Art Database

Contents playback control system by synchronization key

IP.com Disclosure Number: IPCOM000014548D
Original Publication Date: 2002-Mar-01
Included in the Prior Art Database: 2003-Jun-19
Document File: 1 page(s) / 63K

Publishing Venue

IBM

Abstract

This is the disclosure content. This disclosure explains the m edia replay m ethodology w hen the client is connected to the netw ork dedicatedly. T he m edia is distributed freely ,but it needs the authorization keys w hen it is replayed therefore the num ber of replay is controlled by the server even though the m edia exists in the client. T he m edia is devided into m any blocks and encrypted w ith keys w hich decodes each block w hen the series of keys are sent to the user.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 72% of the total text.

Page 1 of 1

Contents playback control system by synchronization key

This is the disclosure content.

This disclosure explains the m edia replay m ethodology w hen the client is connected to the netw ork dedicatedly. T he m edia is distributed freely ,but it needs the authorization keys w hen it is replayed therefore
the num ber of replay is controlled by the server even though the m edia exists in the client.

T he m edia is devided into m any blocks and encrypted w ith keys w hich decodes each block w hen the series of keys are sent to the user.

W hen the user w ants to replay the m edia a series of pair of keys w ill be sent to the player. T he one is for the current block relay key and the other is for the key to encrypt the block after the replay, ,and w hich protects the unauthorized replay.

Also, these pair of keys are encrypted w hen they are transm itted to the user. Fig 1 show s the procedure to decode the m edia and Fig 2 show s the m edia data block.

. Initial values are set then select the record n to replay. (1)
. O btain the block(m ,n) to decode the m edia (3)
. O btain the key to decode block m from the server (4)
. R eplay the m edia after the encryption by key (m ,n) (5)
. O btain the key (m +1,n) to encrypt the above block (6)
. E ncrypt the block (m ,n) w ith the key(m +1,n) (7)
. If the block reached the m axim um then stop the replay of record n (8)

C O NTENTS PLAY BAC K C O NTRO L SYSTEM  BY SYNC HRO NIZATIO N KEY JP 8-2000-0876

M edia records

1

Start a...