WO2000011867A1

WO2000011867A1 - Method for certified delivery of an audio, video or textual sequence

Info

Publication number: WO2000011867A1
Application number: PCT/FR1999/002017
Authority: WO
Inventors: Roland Moreno
Original assignee: Innovatron (Societe Anonyme)
Priority date: 1998-08-19
Filing date: 1999-08-19
Publication date: 2000-03-02
Also published as: FR2782563B1; AU5376499A; FR2782563A1; WO2000011868A1; AU5376599A

Abstract

The invention concerns a method comprising steps which consist in: connecting the apparatus to a remote server (SM); transmitting to this server a sequence-selecting request; receiving in response from said server an encrypted compressed flow of digital signals corresponding to the selected sequence; decompressing and decrypting the flow received and transforming it into an audio, video or textual signal capable of being reproduced and presented to the user. The method further comprises the following steps: writing into the microcircuit memory a debit information corresponding to the selected sequence; transmitting the debit rate to a remote payment site (SC), separate from the server or not; producing a corresponding cryptographic certificate from the payment site; transmitting said cryptographic certificate to the apparatus; verifying by the apparatus the conformity of said cryptographic certificate; if conformity is acknowledged, delivering said decrypted decompressed audio, video or textual signal capable of being reproduced and presented to the user.

Description

CERTIFIED DELIVERY PROCESS FOR AN AUDIO, VIDEO OR TEXT SEQUENCE

The present invention relates to a method for delivering audio, video, text or similar sequences to a remote site by downloading data.

The invention will be described in the context of audio sequences, since this is the most immediate application given the current capacities of broadcasting networks; however, the invention can be transposed directly to the acquisition of other types of sequences, in particular video data (still images or animated television images) or text sequences. It also applies to the acquisition of sequences forming data files of an IT nature, for example data necessary for downloading software, or to allow execution by the user of software requiring a data exchange with a remote site.

Sound reproduction devices can operate from a variety of sources, such as recorded media (discs, tapes, etc.) or transmitted remotely (broadcasting).

These sources all have various drawbacks:

- the use of recorded media presupposes that the user has first moved to buy or borrow them, with of course the difficulties he may encounter in obtaining rare or old recordings, which are difficult to find;

- the broadcast sources, for their part, have the disadvantage of a choice limited to the number of stations received by the user, and of the impossibility of choosing the time to start listening, the user being constrained to the schedules broadcast of the station it receives. Modern data compression techniques make it possible today to transmit sound, and in particular recorded music, via a computer network (for example an Internet network) under excellent technical conditions, that is to say compatible with the highest degree of sound quality today operated everywhere. These possibilities are offered in particular in the case of compression of "MP3" type, with a speed of around 60,000 bps (bits per second), of the same order as that of modems commonly available today, the data being decompressible in real time, at the speed of listening. Even more favorable prospects can even be envisaged with higher speed transmissions such as transmissions on ISDN network or on cable network, or transmission of digitized data by satellite on high speed television channels. These techniques bring together a large number of advantages:

- very wide choice of tracks (musical pieces), - possibility of selecting tracks at will from the installation,

- possibility of choosing when to start listening,

- absence of recorded material support (therefore saving space and lower cost of the device due to the absence of mechanical elements),

- "digital" sound quality, that is to say much better than that of radio broadcasts.

The invention relates more precisely to the payment of broadcasting rights according to the choice made by the user, in the same way as when the latter purchases a recording medium. The object of the invention is to provide a secure method of payment for these rights, making it possible to counter fraud attempts such as downloading without payment of rights or unauthorized reproduction of the sequences.

It also relates to the distribution of these rights between the various music publishers, by seeking to avoid the disadvantages of the payments of rights by the broadcasters, which do not take into account, if not in a statistical therefore approximate way, of the 'real audience at the time of the diffusion of such or such musical range. More specifically, according to a first of its aspects, the present invention relates to a method for delivering audio, video or text sequences to a device of a user cooperating with a microcircuit, in particular a chip card microcircuit, by remote transmission of digital data. representative of these sequences, method comprising the steps consisting in:

- connect the device to a remote server, - send a request to this server for choosing a sequence, - receive in response from this server a stream of compressed and encrypted digital signals corresponding to the chosen sequence,

- decompress and decrypt the received stream and transform it into an audio, video or text signal capable of being reproduced and presented to the user, this process being characterized in that it also comprises the following steps:

- recording in a memory of the microcircuit of flow information corresponding to the chosen sequence,

- transmission of debit information to a remote payment site, whether or not separate from said server,

- production of a corresponding cryptographic certificate by the payment site,

- transmission to the device of this cryptographic certificate,

- verification by the device of the conformity of this cryptographic certificate,

- in the event of recognized conformity, delivery of the data of said audio, video or text signal capable of being reproduced and presented to the user, decompressed and decrypted.

According to various advantageous subsidiary modes of implementation: - the certificate is an intrinsic certificate on which the cryptographic key enabling decryption is applied;

- a right holder information is associated with each sequence information, and the payment site allocates to their respective holders the payments corresponding to the selected sequences; the method further comprises a step of including, by the microcircuit, a watermark in the audio, video or text signal capable of being reproduced and presented to the user, this watermark incorporating an identifier of the microcircuit;

- the audio, video or text signal data are, at the option of the user of the device, delivered in analog or digital form, and the bit rate information is differentiated information according to this choice.

According to a second of its aspects, the present invention relates to a method for delivering audio, video or text sequences to a device of a user cooperating with a microcircuit, in particular a microcircuit of smart card, by teletransmission of digital data representative of these sequences, method comprising the steps consisting in: a) connecting the device to a remote server, b) sending a request to choose this sequence to this server, c) receiving in response from this server a stream of compressed and encrypted digital signals corresponding to the chosen sequence, d) writing to a memory of the microcircuit bit rate information corresponding to the chosen sequence, e) decompressing and decrypting the received stream and transforming it into an audio signal , video or text capable of being reproduced and presented to the user, this process being characterized in that, in step (e), the decryption is carried out by means including said microcircuit used to operate in step (d ) recording the debit information.

Advantageously, this method further comprises a step of including, by the microcircuit, a watermark in the audio, video or text signal capable of being reproduced and presented to the user, this watermark incorporating an identifier of the microcircuit.

0

We will now describe an example of implementation of the invention, with reference to the accompanying drawings.

Figure 1 is a block diagram of the various elements constituting an apparatus for implementing the invention. Figure 2 is a block diagram illustrating a variant of Figure 1, with a higher degree of integration of the elements.

FIG. 3 illustrates the exchange of signals between the different sites or blocks involved in the implementation of the method of the invention.

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In FIG. 1, the reference 10 designates a conventional stereo amplifier / preamp unit supplying a pair of speakers 12. The unit 10 can either be integrated into the rest of the device (which then appears externally in the usual form d '' a high fidelity chain amplifier) or external to this (the device then being in the form of a box of the same type as a CD player, tuner, etc. connected to one of the inputs of a conventional amplifier).

It will be noted that the device can be produced both in the form of a dedicated device (as described here) and as an extension to a microcomputer, or even only consisting of a multimedia microcomputer associated with a player. Smartcard.

The apparatus comprises a display 14 capable of presenting the user with a series of musical tracks, as well as means for selecting these musical tracks, for example in the form of a wheel 16 (for scrolling the tracks) combined with a validation push button 18. The apparatus also includes a programmable processor 20 essentially comprising a central processing unit CPU 22 and a nonvolatile memory MNV 4, independently of its own resources in ROM 26 and RAM RAM 28. The processor 20 receives the selection information and validation from the wheel 16 and the push button 18, and it controls the display 14.

The non-volatile memory 24 can possibly incorporate a hard disk of low volume, if the particular technical constraints impose the need, or be simply constituted by a "solid disk", that is to say a memory large semiconductor, for example 32 MB. The device is also connected to a modem 30 responsible for interfacing the device with the telephone network 32, typically at a speed of 56,000 bps. The apparatus also comprises a switching circuit 34 allowing the selection between, on the one hand, the reception of an audio source by the modem 30 and, on the other hand, the other usual inputs of the amplifier (CD, tuner , cassette, etc.) grouped together in the drawing in the form of an "auxiliary" input 36. The processor 20 is also connected to a smart card 38, the role of which will be explained below, by means of a reader 40.

The use of this device takes place essentially as follows. On power-up, for example by pressing the button 18, the device automatically connects via the telephone network 32 to a remote site or "nightclub site", whose address, Internet or other, is permanently saved in non-volatile memory 24. The main program controlling the processor 20 then allows "navigation" on this site, this program incorporating for example a subset of conventional navigation software, specially adapted and simplified for the needs of the device of the invention. The user will thus navigate in a directory of musical tracks, which he will be able to scroll through and select using the wheel 16 and the push button 18.

If necessary, the navigation system and the display can be adapted to facilitate access by selection of musical genres or sub-genres, or by cross-selection between musical genres (classical, jazz, opera, etc.) and type. of works (original editions, new releases, titles most / least requested, etc. .. The display 14 can then be in the form of a table with double entry selectable by appropriate commands on the abscissa and on the ordinate (touch screen , double row of buttons, etc.) used to designate a row / column intersection.

Once the selection of the musical track has been made, the processor 20 sends an order to the remote site in order to allow the downloading of the chosen musical track. This download can be carried out in real time (hearing as and when it is loaded) or almost real, by providing a buffer in the processor, for example to increase the decompression and / or decryption performance.

The smart card 38 is used to enable the decryption and, optionally, the payment of the rights attached to the musical work of the selected track.

It may be advantageous to use a structure such as that illustrated in FIG. 2, having a higher degree of integration - and therefore greater security against fraud. The security / decryption / payment circuits are included in a block 42, advantageously produced in the form of a monolithic assembly, integrated circuit or hybrid circuit embedded in a protective material preventing any non-destructive access to the elements of the circuit.

This block 42 comprises a microcircuit 44 receiving the identification information 52 of the raw stream (that is to say encrypted and compressed) coming from the modem 30 and responsible for generating the keys 48 necessary for decryption, and constituted typically only by the microcircuit of a smart card. As a variant, it can be constituted by a module of the so-called SAM (Security Access Module) type, possibly associated with other SAM modules in the decoder. The block 42 also includes a decryption module 50 receiving the musical information 52 from the raw stream coming from the modem 30 and processing the latter by means of the keys 48 to output a stream 54 decrypted and compressed. The block 42 also includes a decompression module 56, for example of the MP3 type at 44.1 kHz, 16 bit stereo, at a rate compatible with listening in real time, delivering the decrypted and decompressed data stream as output. 58 applied at the input of amplifier 10.

In an implementation variant, digital output of the data is provided, advantageously in a prescribed standardized format such as the SDMI (Secure Digital Music Initiative, the specifications of which are published on the website vvww.sdmi.org). This format may include an identifier, advantageously coming from the smart card and, moreover, the payment of the fees may be different depending on whether this digital output is activated or not.

In a particularly advantageous implementation, it is the same card 38 which is used not only for decryption, but also for the payment of the rights attached to the musical work. This payment can be made using known telegram procedures such as "cybercash", "virtual-money", etc.

The data to be exchanged to allow payment are illustrated schematically in Figure 3. This payment process involves exchanges of signals between the following points:

- SM "musical" site, which is a website specific to the music publisher corresponding to the chosen musical track,

- SC corporate site, common to the various publishers participating in the system and responsible for distributing the rights between them,

- non-volatile memory MNV of the device, for temporary storage of data,

- SOFT software of the device,

- smart card 38, - amplifier 10. The different steps referenced 1 to 7 in the figure are as follows: 1. The musical site SM corresponding to the track selected by the user sends the device an MP3 file, or an MP3 data block, to the device, which stores this information in its non-volatile memory MNV. 2. The exchange of data between the device and the smart card (stream 2 and 2 ') performs a first decoding of the data, operated in block 50 of FIG. 2.

3. The device then writes debit information to the memory of the smart card, corresponding to the selected track and the corresponding music editor.

4. The device connects to the SC corporate site; the debit information stored in step 3 is then transmitted to the corporate site, which issues a cryptographic certificate.

5. This cryptographic certificate is transmitted to the decoder, which verifies its conformity and, if this is the case, authorizes the issue (step 6 below) of the decompressed and decrypted data.

6. Conditionally (see step 5 above), the software delivers the data to be listened to, decompressed and decrypted.

7. At regular intervals, the corporate site credits the individual music publisher with the rights debited from the device.

Verification of the cryptographic certificate in step 7 can be carried out by the card itself or, optionally, by a separate SAM circuit. Furthermore, in a particular embodiment, the certificate can be an intrinsic certificate, that is to say which functions the cryptographic key which will allow the decryption of the data to be listened to.

Debit can be operated by various known means: use of a prepaid card (account card), a subscription card with subsequent debit from the subscriber, for example on the invoice he receives from his Internet provider , loyalty system, free promotional slots, etc.

The payment process can be summarized by the following metalanguage algorithm. Amplifier: while counter> Max

Exec (Payment_Process) Exec Receive_New_Key) wend

Exec (Pay_Then_Decode) END Remote site:

Receive_Card_Counter while Counter> Max

Exec Payment_Process wend

Download_Music return

Payment Process (amplifier): Payment_Process_Protocol if payment is NOT OK then END Receive_New_Key return

Payment Process (remote site):

Receive_Royalties_Data from Card if Royalties_Data is NOT OK then END Debit_Customer_Royalties_Sum Credit_Publisher

Send_New_Key set Card_Counter = 0 return

Furthermore, in an alternative embodiment, it will be possible to exploit the cryptographic possibilities offered by the combination of three particular data (or data sources):

- card identity;

- operating data (digital music); - random seed (fixed or periodic). Thus, modulation can be made function of an identity specific to the amplifier-client, that is to say undecodable by an intruder who would try unduly to decode the musical tracks which are not intended for him. In addition, such a device would allow pricing proportional to the listening time, since the periodicity of the random seed could be sufficiently brief. For example: a unit of account every sixty seconds.

In a particular implementation, it is possible to provide for the inclusion of a "watermark" (watermarking) in the data flow. The technique of including a "watermark" or "tattoo" is in itself known, and described for example in Petitcolas et al., Information Hiding

- a Survey, Proceedings of the IEEE, 87 (7): 1062-1078, July 1999, or Boney et al., Digital Watermarks for Audio Signais, European Signal Processing Conférence, EUSIPCO '96, Trieste, Italy, September 1996, as well than in US-A-5,828,325, US-A-5,613,004, US-A-5,687,191 and US-A-5,822,360, or in presentations of Aris Techologies Musicode systems (www.musicode. com) and Audiomark from Alpha Tec Ltd. (www.alphatecltd.com). The invention however proposes to implement it: - at the musical site, to "watermark" or "tattoo" the coded data stream (compressed and encrypted) broadcast to the user, and / or

- at the decoder, locally and within the card itself during decryption and decompression operations, to "watermark" or "tattoo" the decrypted and decompressed data stream at output, the watermark incorporating an identifier of the card used to decrypt and decompress this data. In general, this technique consists of adding inaudible information to the musical message, but which can be revealed by appropriate techniques. For an analog signal, the simplest technique combines by adding a low level identification signal coding the identification information in a very redundant manner, for example by adding a carrier of 10 kHz of level inaudible with respect to the musical message. and modulated in phase at 100 bits / s; the revelation is done by filtering techniques with correlation. For a digital signal of the operations of same nature can be done digitally. More simply, the identification message can be multiplexed with the original message and ignored during sound reproduction (but in this case the identification message can be easily removed).

Many techniques exist aimed at making the tattoo undetectable, difficult to remove or hide, and little alteration of the message. Some allow tattooing of compressed music in digital form without even decompressing it, which is well suited to the case of the invention.

Claims

1. A method for delivering audio, video or text sequences to a device of a user cooperating with a microcircuit (44), in particular a chip card microcircuit (38), by remote transmission of digital data representative of these sequences, method comprising the steps of:

- connect the device to a remote server (SM),

- send a sequence selection request to this server, - receive in response from this server a stream of compressed and encrypted digital signals corresponding to the chosen sequence,

- transmission of debit information to a remote payment site, separate (SC) or not from said server, - production of a corresponding cryptographic certificate by the payment site,

- transmission to the device of this cryptographic certificate,

- verification by the device of the conformity of this cryptographic certificate, - in the event of recognized conformity, delivery of the data of said audio, video or text signal capable of being reproduced and presented to the user, decompressed and decrypted.

2. The method of claim 1, in which the certificate is an intrinsic certificate on which the cryptographic key enabling decryption is used.

3. The method of claim 1, in which a right holder information is associated with each sequence information, and in which the payment site allocates them to their respective holders. elements corresponding to the selected sequences.

4. The method of claim 1, further comprising a step of including, by the microcircuit, a watermark in the audio, video or text signal capable of being reproduced and presented to the user, this watermark incorporating an identifier microcircuit.

5. The method of claim 1, in which the data of the audio, video or text signal are, at the option of the user of the device, delivered in analog or digital form, and in which the information of flow is differentiated information according to this choice.