GB2432434A

GB2432434A - Transfer of digital content in a copyright and royalty protecting system

Info

Publication number: GB2432434A
Application number: GB0522617A
Authority: GB
Inventors: Paul Nicholas Smith; James Boyd Campbell
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-11-05
Filing date: 2005-11-05
Publication date: 2007-05-23
Also published as: GB0522617D0

Abstract

A method of transferring data files in a network. The method comprises requesting a data file from a content provider at a computing device; transmitting a locked (encrypted) data file from the content provider to the computing device; authorising a payment to the content provider; transmitting an unlock code (decryption key) to the computing device in response to said payment; and unlocking (decrypting) the locked data file at the computing device such that the locked data file can be opened on the computing device. A method of receiving data files at a computing device, a method of transmitting data files from a content provider are also disclosed, a system for transferring data files in network, a computing device and a content provider apparatus are also disclosed. Further embodiments relate to the network being a wireless network with wireless computing devices. The payment may be made by way of SMS message. Previewing of the data files may also be embodied as an unlocked portion of the locked data file. The claims also contain features related to royalty payments and comission payments particularly if the content is distributed among computing devices themselves (i.e. forwarded from a first computing device to a second computing device). Further embodiments disclose computing devices being able to upload content and/or playlists to the content provider.

Description

METHOD OF TRANSFERRING DATA FILES IN A NETWORK

The present invention relates to a method of transferring data files in a network. In particular, but not exclusively, the invention relates to a method of enabling secure payment for digital data files transferred over a wireless connection from a content provider to a wireless computing device.

It is well known that digital data files such as music, audio, video, still images and text can be downloaded to a wireless computing device over a wireless network.

The digital data may commonly comprise business data, presentations, text, mobile telephone ringtones, wallpapers, screen savers or icons. The digital data may be digital media made available in a number of industry standard encrypted and compressed forms, as appropriate to the content of the digital data, for instance, MP3, MP4, AAC, ATRAC, WMA, MPEG, JPEG and BMP.

Wireless computing devices include mobile telephones, wireless enabled personal digital assistants (PDAs) and wireless enabled digital media players. Due to technological advances there is now a wide range of cheap, compact and portable wireless computing devices available to consumers. Consequently, the practice of downloading digital data files is becoming increasingly popular.

The wireless network used to download digital data may, for instance, be a wide area wireless network, operating using a standard telecommunications protocol such as the global standard for mobile communications (GSM) or CDMA.

Alternatively, or in addition, the wireless network may use a short range wireless protocol such as wireless local area networking (WLAN) or Bluetooth. The wireless network may be a public network, for instance a OSM mobile telephone network.

Alternatively, the network may be a private network, for instance a WLAN corporate intranet. The network may incorporate both public and private elements. Increased data rates in wireless networks, for instance the spread of publicly accessible WLAN "hotspots", has helped to make downloading data files a fast and efficient process.

However, one of the key challenges facing those participating in, and driving, this growing market in wireless distribution of data files is how to ensure that copyright holders receive royalty payments due to them from the sale and distribution of digital media. There are a number of existing digital data content providers already offering digital media download services over wireless networks. While many do

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apply digital rights management (DRM) techniques to protect the copyright holders, there are a significant number that do not provide a mechanism for ensuring royalty fees are paid. Furthermore, there are a number of significant problems with existing DRM techniques in this context.

It is known to provide a system whereby a user makes a payment to a content provider, and in return receives a digital media file over a wireless network. The payment is then distributed between the content provider and the copyright holder (and also, if necessary, the network operator). For instance, in a GSM mobile telephone network the payment may be made by a user via the short messaging service (SMS). The SMS service incorporates a premium messaging service, in which the user is charged a rate over an above the normal network SMS rate. The network operator forwards part of revenue to the content provider. Upon receipt of a premium rate SMS the content provider sends a digital media file to a user, for instance contained within another SMS message or via an alternative data protocol such as the general packet radio service (GPRS). The user is then able to open and store the digital media file on their wireless computing device. Alternative mobile telephone standards, for instance CDMA, also provide messaging services with functionality similar to SMS, and data transfer protocols.

There are a number of peer-to-peer networks operating through publicly accessible websites, which allow users to freely transfer downloaded digital media files (perhaps downloaded from other content providers for an initial fee) without making a payment. One of the challenges of DRM is limiting onward peer-to-peer transfer of legitimately downloaded and paid for digital media files, or ensuring that such transfer incurs further payment. For instance, in the above described scenario of downloading a data file in response to a premium rate SMS message, there may be nothing to prevent a user from forwarding the digital media file to a third party, thereby circumventing the payment mechanism.

In a further known system described in PCT patent application publication number WO 03/075584 (Nokia Corporation) a user requests a digital media file from a content provider and receives the digital data file in a format that can be opened (and played), but not saved, on the wireless computing device. In order to allow the digital data file to be saved the user must make a payment to the content provider. In return, the user is given an appropriate license key allowing the digital media file to be stored for later use. However, ultimately, the user still has access to a stored playable version of the digital media file, which could be transferred to another user, thus circumventing the payment mechanism.

US patent application publication number US 2004/0024688 (Bi et al) describes a system in which a user subscribes on a monthly basis to a content provider, and in return can download a predetermined number of data files. Each file is in a locked format that cannot be opened on a computing device without a separately downloaded time-limited license key. Each data file may be opened using the key for a predetermined length of time until the key expires, at which time the locked file can no longer be opened. Such a system is inflexible in that it requires a pre-existing relationship between a user and the content provider. As such it does not provide for spontaneous purchase by users, nor is there the flexibility to download digital media files from a plurality of content providers without a pre-existing relationship with each content provider.

Such a subscription service typically requires access to a credit card or bank account for payment to the content provider. This requirement can create a barrier to potential users of the service. Hitherto, digital data file download services have typically operated on a subscription basis due to the cost overheads associated with the collection of large numbers of low value payments. For such "micropayments" it is uneconomic to have each payment processed via a credit card, as the credit card processing fee (payable to credit card operators) may in some circumstances be comparable to, or greater than, the size of the payment.

With mobile telecommunication networks it is often possible to have a pre-paid account in which a set amount of money is deposited with the network operator.

Call and data charges are debited from the deposited money. Such a system does not require a credit card or bank account or a specific debit or credit account with the content provider. It would be advantageous if all that was required to download and pay for data files from a content provider was, for instance, a valid pre-paid or credit account with a wireless network operator.

It is an object of the present invention to obviate, or mitigate, one or more of the above problems. Specifically, it is an object of embodiments of the present invention to provide a method and system for securely downloading and paying for a digital media file. It is an object of embodiments of the present invention to provide a method of initiating and reconciling payment for downloaded digital data files using messaging services inherent in the wireless network, for instance SMS. It is a further object of embodiments of the present invention to provide a method of tracking downloaded data files, such that if transferred to a third party wireless computing device the content provider can ensure further payment (if required) is made.

According to a first aspect of the present invention there is provided a method of transferring data files in a network and a system for transferring data files in a network. The method comprises requesting a data file from a content provider at a computing device; transmitting a locked data file from the content provider to the computing device; authorising a payment to the content provider; transmitting an unlock code to the computing device in response to said payment; and unlocking the locked data file at the computing device such that the locked data file can be opened on the computing device.

An advantage of the present invention is that a downloaded data file cannot be opened without a payment being made to the content provider. Additionally, if the locked data file is transferred to another wireless computing device then it cannot be opened on that wireless computing device without a further unlock code being provided by the content provider. If appropriate, a further payment may be required to gain the extra unlock code. The payment authorisation and subsequent transmission of the unlock code allows the content provider to keep track of each downloaded data file. A payment on demand mechanism provides an efficient transaction process. This allows for the spontaneous purchase of data files, for instance digital media files, without requiring a pre-existing relationship between the user of a wireless computing device and a content provider, or the need to register, provide credit card / bank details or make a pre-payment to the content provider.

Using the inbuilt messaging service of the wireless network provides pre-existing robust and reliable communications channel allowing a content provider to rapidly deliver data file download services.

Said network may comprise a wireless network and said computing device may comprise a wireless computing device.

Transmitting the unlock code to the computing device may comprise transmitting the unlock code from the content provider to the computing device.

Preferably, the method further comprises receiving at the computing device a lock code, the lock code being ananged to prevent the locked data file being opened on the computing device without the unlock code.

Preferably, the method further comprises receiving at the computing device payment information which indicates the value of the payment to be authorised to the content provider in order to receive the unlock code in response to said payment.

Preferably, the method further comprises assigning a data file identifier at the content provider to the locked data file; and receiving the data file identifier at the computing device.

Preferably, the method further comprises providing the data file identifier from the computing device to the content provider when authorising the payment to the content provider, such that the content provider can reconcile the payment to the locked data file.

Preferably, the method further comprises assigning a device identifier to the computing device.

Preferably, the method further comprises maintaining a device database, the device database comprising a plurality of records, each record comprising an entry for the device identifier of each of a plurality of computing devices.

The method may further comprise the content provider updating the device database record for a device identifier to indicate that the computing device has received a locked data file.

The method may further comprise updating the device database record for a device identifier to indicate that the computing device has authorised a payment to the content provider.

The method may further comprise updating the device database record for a device identifier to indicate that the computing device has received the unlock code from the content provider.

Preferably, the method further comprises receiving at the computing device a media player from the content provider, the media player being adapted to receive the unlock code from the content provider and unlock the locked data file, wherein receiving the media player from the content provider assigns the device identifier to the computing device.

Preferably, the method further comprises transmitting information identifying the user of the computing device from the computing device to the content provider; and updating the device database record for the device identifier with the information identifying the user of the computing device.

Preferably, the unlock code is dependent upon the device identifier and the data file identifier, such that only the computing device assigned that device identifier can unlock the locked data file assigned that data file identifier.

Preferably, the method further comprises receiving a prompt message to authorise the payment to the content provider at the computing device after the computing device has received the locked data file.

Preferably, authorising the payment to the content provider comprises transmitting a payment message to the content provider from the computing device in response to the prompt message.

If a user associated with the computing device chooses not to authorise the payment to the content provider then the method may comprise transmitting a time out message to the content provider from the computing device at a predetermined period of time after the prompt message.

The method may further comprise updating the device database record for the device identifier to indicate that the computing device has not authorised a payment to the content provider.

Preferably, the content provider further comprises a data file database, the method further comprising accessing the data file database and selecting the locked data file at the computing device.

Authorising a payment to the content provider may comprise sending an SMS message from the computing device to the content provider. Preferably, the SMS message comprises a premium rate SMS message.

Authorising a payment to the content provider may comprise authorising a payment from a debit or credit card account associated with a user of the computing device to the content provider.

Preferably, the method further comprises paying a royalty fee from the content provider to the copyright holder of the locked data file in response to said payment.

The method may further comprise transmitting the locked data file from a first computing device to a second computing device.

The method may further comprise transmitting the device identifier of the first computing device from the first computing device to the second computing device.

The method may further comprise checking the records in the device database for the device identifiers of the first and second computing devices to determine whether the information identifying the users of the computing devices is the same.

The method may further comprise receiving an unlock code at the second computing device from the content provider; and unlocking the locked data file at the second computing device such that the locked data file can be opened on the second computing device.

The method may further comprise authori sing a payment from the second computing device to the content provider; and transmitting the unlock code to the second computing device in response to said payment.

The method may further comprise receiving a commission payment from the content provider at the first computing device in response to said payment from the second computing device. The method may further comprise transmitting from the content provider to the computing device a preview field, the preview field containing a portion of the locked data file in an unlocked format.

The method may further comprise assigning a content provider identifier to each of a plurality of content providers; and receiving the content provider identifier at the computing device.

The method may further comprise transmitting a data file to a content provider from a first computing device; and making said data file available as a locked data file at the content provider for transmission to other computing devices.

The method may further comprise paying a royalty payment from the content provider to a user associated with the first computing device in response to a payment authorised by another computing device.

The method may further comprise transmitting a playlist to a content provider from a first computing device; and making data files contained within the playlist available as locked data files at the content provider for transmission to other computing devices.

The method may further comprise paying a commission payment from the content provider to a user associated with the first computing device in response to a payment authorised by another computing device.

According to a second aspect of the present invention there is provided a method of receiving data files at a computing device and a computing device arranged to receive data files. The method comprises requesting a data file from a content provider; receiving a locked data file at the computing device from the content provider; authorising a payment to the content provider; receiving an unlock code at the computing device in response to said payment; and unlocking the locked data file such that the locked data file can be opened on the computing device.

According to a third aspect of the present invention there is provided a method of transmitting data files from a content provider and a content provider apparatus arranged to transmit data files. The method comprises receiving a request for a data file at the content provider from a computing device; transmitting a locked data file to the computing device; receiving notification that a payment to the content provider has been authorised; and transmitting an unlock code to the computing device in response to said payment such that the computing device can unlock the locked data file open the locked data file on the computing device.

It will be understood that the methods and systems and devices of the present invention can be implemented in a variety of forms. These forms include a carrier medium carrying computer readable code for controlling a computer to carry out the method. The forms also include a computer apparatus for implementing the method, the apparatus comprising: a program memory storing processor readable instructions; and a processor configured to read and execute instructions stored in said program memory; wherein the processor readable instructions comprise instructions controlling the processor to carry out the method.

The present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a flow chart schematically illustrating a process for downloading a digital data file to a wireless computing device in accordance with an embodiment of the present invention; Figure 2 schematically illustrates a system for downloading digital data files in accordance with an embodiment of the present invention; Figure 3 is a flow chart schematically illustrating a process for downloading a digital data file to a wireless computing device using the system of Figure 2; Figure 4 schematically illustrates messages passed between a wireless computing device and a content provider during the process of downloading a digital data file to a wireless computing device illustrated in Figure 3; Figures 5a to 5h schematically illustrate the format of messages passed between the wireless computing device and the content provider in Figure 4; Figure 6 is a flow chart schematically illustrating a process a forwarding a digital data file from a first wireless computing device to a second wireless computing device using the system of Figure 2; Figure 7 schematically illustrates messages passed between the first wireless computing device, the second wireless computing device and the content provider during the process of forwarding a digital data file from the first wireless computing device to the second wireless computing device illustrated in Figure 6; and Figures 8a and 8b schematically illustrate the format of messages passed between the first wireless computing device, the second wireless computing device and the content provider in Figure 4.

Embodiments of the present invention provide a method and system for enabling secure payment for data files transferred to wireless computing devices over a wireless network allowing a content provider to reconcile that payment to the downloaded data file. A user, via a wireless computing device, is able to search for and select data files, typically digital media files, download a locked data file to the wireless computing device from a content provider and pay the content provider for the downloaded data file. Once the payment has been authorised, the content provider transmits an unlock code to the wireless computing device allowing the user to open the locked data file.

The user can also forward the locked data file to another wireless computing device. The other wireless computing device may be owned by the same user or a third party. When the data file is forwarded to a wireless computing device owned by a third party, a further payment to the content provider may be required before that wireless computing device can unlock the locked data file. The user forwarding the data file may be entitled to receive a commission, upon payment being received by the content provider from the third party.

Referring to Figure 1, this schematically illustrates the process of selecting, downloading, paying for, forwarding and tracking data files. At step 1, a user accesses a content provider's website. The content provider's website may be a publicly accessible website, or it may be part of a corporate intranet. Typically, the website is accessed via a wireless network using a web browser optimised for use on a wireless computing device. Once connected to the website, the user is able to search for, and select, the required digital data file at step 2.

Once the user has selected the desired data file a locked copy of the data file is packaged into a specific data format for delivery at step 3. The package contains the locked data file and a unique data file identifier. The data file identifier is used to allow the content provider to reconcile later payment for the downloaded data file and for tracking the locked data file, as will be explained in more detail below. The package may also include payment data (i.e. a price associated with the data file), or this may be sent in a separate message. The package is then transmitted over the wireless network to the wireless computing device at step 4.

Once the locked data file is received at the wireless computing device, the content provider sends a prompt message to trigger payment at step 5 (or this may form part of the original package transmitted at step 4). If the user chooses to accept the locked data file, the user authorises payment to the content provider at step 6. The payment may be made using the inbuilt messaging service of the wireless network, for instance it may be a premium rate SMS message. The SMS message is received by the content provider, which, in cooperation with the wireless network operator, receives payment from the user's account with the wireless network operator.

The charge may be added to the users monthly bill, or it may be debited directly from the account of a pre paid wireless network user. The premium rate SMS message would typically be identified as such to the user in their next account statement. The cost of the premium rate SMS message may be variable, according to the data file that is downloaded. In addition, the cost may vary if the locked data file has been forwarded from another wireless computing device, rather than downloaded from the content provider. The process of forwarding locked data files is discussed in more detail below with reference to Figures 6-8. The price may be dynamically set, for instance by varying the return address contained in the prompt message such that the cost of the reply premium rate SMS payment authorisation message varies, as determined by the return address. Alternatively, the cost of the premium rate SMS payment may be dynamically set by the content provider, while the return address remains constant.

Additionally, once payment is received, the content provider tracks the downloaded data file by maintaining a device database including information relating to which locked data files each wireless computing device has downloaded, in order to monitor the distribution of data files. The device database can be checked later in order to ensure that future required payments are made. Details of which data files each wireless computing device downloads are stored in the device database using a unique data file identifier assigned to each data file by the content provider.

At step 7 the content provider receives notice of the authorised payment, reconciles the payment with the downloaded locked file and transmits an unlock code to the wireless computing device. The user is then able to unlock the data file and open / play the locked data file using the unlock code at step 8. Without the unlock code the user is able to store the data file, but not open it. Thus, the act of sending the payment authorisation, (e.g. the premium rate SMS), unlocks the data file allowing it to be played on the wireless computing device. The user is then free to open / play the unlocked data file as many times as they wish.

At step 9 the system allows the user to forward the data file to other wireless computing devices owned by themselves or other users. This may be in order to make back-up copies of the locked data file on other wireless computing device, or data carriers, owned and registered to the same user, in which case there may be no requirement for further payment. The data file may be forwarded via a similar process to the original download, i.e. over the mobile network, or it may be via a separate mechanism, for instance a wired link or a peer-to-peer short range wireless connection e.g. WLAN, IRDA or Bluetooth. This triggers a further payment request to the new wireless computing device at step 5. The payment process continues as before. The new user is also able to forward the data file to other wireless computing devices.

The user that forwards the data file at step 9 may be entitled to a commission payment, once payment for that data file has been received from the new wireless computing device. This aspect of the present invention is in marked contrast to current methods and systems of downloading data files to wireless computing devices, in which the ability of end users to distribute the data files further is often seen as a negative aspect. This is because in current systems there is no mechanism to require other users to make a payment to the content provider when they receive a data file from an end user. in some systems according to the present invention, payment by third parties to the content provider for peer-to-peer distributed data files is enforced by the necessity of receiving an unlock code from the content provider. By providing a commission to users for forwarding data files, greater distribution of the data file is encouraged, and consequently more payments to the content provider are made than might otherwise be the case.

Referring now to Figure 2, this schematically illustrates a system for downloading locked data files to a wireless computing device in accordancewith an embodiment of the present invention. Wireless computing devices 20 (illustrated as a mobile telephone 20A and a PDA 20B) are wirelessly connected via a wireless network 21 (e.g. a mobile telecommunications network) to content provider 22. Each wireless computing device 20 has a web browser installed, in order to access and search the data files held by the content provider 22.

Content provider 22 consists of the following components: mobile gateway 23, content server 24, payment server 25, security server 26 and download server 27.

The mobile gateway 23 acts as the primary interface between the mobile network 21 and the content provider 22. The mobile gateway 23 also provides a web server for allowing the wireless computing device 20 to access a data file database 28 of data files that can be downloaded.

The security server 26 manages the lock and unlock codes for the data files, and the identifiers for the content provider 22, data files and wireless computing devices 20 (described in more detail below). If a user registers their wireless computing device with the content provider 22 then the security server 26 passes the wireless device identifier of that wireless computing device to the download server 27 to update a device database 29. The security server 26 also handles the downloading of a software media player to the wireless computing device 20, for handling the downloading of data files to the wireless computing device 20. The functions of the media player are described in more detail below.

The content server 24 controls the main functions of the content provider 22, including handling user requests (e.g. searching the data file database 28 for data files). The content server 24 also manages the interaction between the other components of the content provider. Effectively, the content server 24 is the front end interface to the wireless computing device. The download server 27 manages the downloading of the data files from the content provider 22 and maintains a register of the identifiers for each registered wireless computing device in the device database.

Additionally, the download server 27 manages royalty payments to the copyright holders of the data files and tracks the further peer-to-peer distribution of data files.

Payment server 25 acts as the interface between the content provider 22 and the billing systems of operators of the mobile network 21. A proportion of the revenue received by the mobile network operator for premium rate SMS messages from the wireless computing devices 20 is passed to the content provider 22. Subsequently, a proportion of this revenue is passed by the download server 27 to the copyright holders for the digital data files. The payment server 25 is also able to handle a range of alternative payment methods, for instance payment from a credit or debit card, or other payment methods known in the art.

It is to be understood that the various components of the content provider 22 are merely logical subcomponents. In reality, they may in fact all be implemented on a single physical server. If they are implemented on physically distinct servers, the servers may be widely separated, connected together by a computer network.

The content provider preferably implements DRM in compliance with the DRM requirements specification issued by the Open Mobile Alliance (OMA) although it will be appreciated that other DRM systems could be used. This does not mandate any particular DRM implementation, but does require that it is possible to charge users per item of digital media downloaded. The present invention provides a comprehensive DRM system providing for secure payment in accordance with the OMA DRM requirements, by distributing locked data files that may only be unlocked upon secure payment to the content provider. The mechanism for locking and unlocking data files and distributing unlock codes will be explained in more detail below with an exemplary data file download scenario.

Each wireless computing device is assigned a unique device identifier for tracking purposes. The device identifier is used to identify the wireless computing device when purchasing or forwarding data files. It is contained in all messages to or from the content provider or passed between wireless computing devices. The content provider updates the device database with details of all download and forwarding activity for each device identifier. This may be anonymous, or users may register their details for each device identifier. Registration is required for certain features of embodiments of the present invention, for instance, gaining commission for forwarding data files to other users or uploading data files to the content provider (discussed in more detail below). The device identifier may be linked to the hardware of the wireless computing device, for instance assigned during manufacturing.

Alternatively, the device identifier may be linked to software installed on the wireless computing device for downloading and unlocking the locked data files. The software installed on the wireless computing device, referred to generally as a media player, enables the secure download, payment, unlocking, opening and forwarding of locked digital data files such as digital media files.

The media player may either be embedded during manufacture of the wireless computing device (for instance if the present invention were to be adopted as an industry standard), or it may be downloadable, either over the wireless network, or via a temporary wired connection. The media player may be a stand alone proprietary software application or an extension or plug-in to a third party media player application, to provide the additional downloading and unlocking functionality.

Once downloaded and configured, the media player allows users to seamlessly browse, select, download, purchase, unlock and open digital media files. In certain embodiments of the invention the media player also allows the user to preview part of the digital media file, before deciding whether or not to purchase the digital media file. As the media player handles the unlocking of the locked data file automatically, the user need not be aware that this process takes place. In addition to opening or playing data files the media player is also responsible for basic file management functions and compiling the messages required to be passed to the content provider or other wireless computing devices. The media player supports multiple file formats, as appropriate to the type of media, for instance including MP3, MP4, AAC, ATRAC, WMA, MPEG, JPEG and BMP.

The media player is able to access and download data files from more than one content provider. Each content provider is assigned a unique content provider identifier in order to ensure messages between the content providers and the wireless computing devices are handled correctly.

In certain embodiments of the present invention users will be able to upload data files from their wireless computing device to a content provider. A data transfer protocol used by the wireless network, for example GPRS for GSM, is used to upload data files from a wireless computing device to the data file database server at the content provider. To utilise the upload service the user registers with the content provider. The content provider provides a pre-determined amount of storage space for each user. Users may purchase increased storage space. The content provider provides access to the server to allow users to manage their data and view usage records.

These uploaded data files will be available for download by other users in the normal manner. Copyright royalty payments derived from the payments from the other users for downloading the data files are passed to the user that uploaded the data file (as that user has registered their details in the device database entry for the device identifier for their wireless computing device). Preferably, users uploading data files to the content provider should be checked to ensure that they own the copyright to the data files before receiving copyright royalty payments. Additionally, users are able to upload "playlists" (typically, for selections of music files such as MP3s) to a content provider. When another user selects a data file for download from a playlist the user who uploaded the playlist to the content provider will receive a commission.

In order to be able to receive commission payments when other users download data files that a first user has uploaded or listed in a playlist, the first user would need to be registered with the content provider. The content provider tracks the distributed data files and reconciles the associated payments made when they are downloaded. As a first option, commission payments may be credited to the first user's account with an operator of the wireless network. This would be preferable if the operator was also the content provider. Alternatively, an account associated with the content provider is credited with the commission payments.

The act of uploading a playlist results in an entry being made in the data file database for each data file identifier in the playlist. When a data file in the playlist is downloaded to another wireless computing device, and a payment made, the database held by the content provider for each wireless computing device identifier is updated to show that a commission or royalty payment is payable to the user associated with the wireless computing device identifier that uploaded the data file or playlist.

Referring now to Figure 3, this illustrates in the form of a flow chart the process of downloading a data file to a wireless computing device, and paying for the data file in a typical embodiment of the present invention. In summary, the unlock code is sent to the media player in response to the purchase prompt message and various subsequent message exchanges shown in Figure 3. When the locked data file is downloaded, the user is prompted to purchase the file. When the user accepts the locked data file, a purchase request message is generated which requests the unlock code from the server. This unlock code takes the form of a symmetric decryption key, which is applied to decrypt the downloaded file, and is sent in an SMS message. No further interaction or acceptance is required from the user to decrypt the file, and the message is automatically routed to the media player within the wireless computing device.

At step 30 the user downloads the media player to the wireless computing device. The downloaded media player contains the unique device identifier. The user then optionally sends a message to the content provider to register the wireless computing device at step 31. Downloading the media player and registering the computing device at steps 30 and 31 need only be done once for each wireless computing device. For subsequently downloaded data files the process begins at step 32.

At step 32 the user downloads a locked package from the content provider.

The file contains the locked data file, a lock code and the data file identifier. A symmetric key scheme is used to encrypt the data file before it is downloaded. This is termed the lock code. Additionally, an asymmetric scheme is used to encrypt the download package' (message 49), containing the locked data file and the data file identifier (ID), which is downloaded to the wireless computing device. The media player is able to decrypt the download package, but not the locked data file. In order to unlock the data file the wireless computing device must request the unlock code' (the corresponding part of the symmetric key) from the content provider.

For simplicity, the sub steps of accessing the content provider database and searching for a particular data file are not illustrated in Figure 3.

At step 33 the content provider sends a prompt message to the wireless computing device to prompt the user to authorise a payment (or this may be part of the earlier download package). Alternatively, a prompt message could be internally generated within the wireless computing device. The user responds to the content provider with a purchase request, which contains the device identifier, the data file identifier and the lock code. The purchase request may, for a GSM wireless network, be sent as an SMS message. The purchase request may be encrypted or signed to authenticate the user to the content provider.

At step 34 the content provider responds to the purchase request with payment information including the cost of the data file, or a price list if a plurality of data files are being downloaded. The price list also includes the device identifier, the lock code and the data file identifier. The payment information or the price list may be dynamically updated by the content provider to reflect the value of the data file.

At decision step 35 the user must decide whether or not to authorise the payment. If no payment authorisation is made then the system times out at step 36 and the process ends. Alternatively, the user may authorise the payment at step 37 by sending a message to the content provider, typically in the form of a premium rate SMS message. The payment authorisation message will contain the device identifier, the data file identifier and payment authorisation. In response to the payment authorisation the content provider sends the unlock code to the wireless computing device at step 38. The wireless computing device uses the unlock code to unlock the data file such that it may be opened or played. Step 38 may happen automatically, without requiring any interaction from the user.

Figure 4 illustrates the message flows associated with the above data file download scenario. In message 40 the wireless computing device sends a request to the content server to download a media player. The content server forwards the message to the security server in message 41. The security server creates an entry in the device database (message 42) using the assigned device identifier to create a new user record. If the user then chooses to register their details with the content provider (not shown) then this information is added to the device database. The security server also transmits the media player to the wireless computing device, including the device identifier (message 43).

In message 44, the wireless computing device requests a data file from the content provider. The content server forwards the request to the download server in message 45. The download server updates the device database with the request (message 46) and retrieves the locked data file from the data file database (messages 47 and 48). The download server forwards the locked data file to the wireless computing device in message 49.

In message 50 the user makes a purchase request to the content server, which forwards the request to the payment server (message 51), which in turn updates the device database (message 52). The payment server sends the payment information to the wireless computing device (message 53).

If the user decides to authorise the payment then message 54 is sent to the content server and forwarded to the payment server (message 55), which updates the device database (message 56). The security server returns the unlock code to the wireless computing device in message 57.

Alternatively, if the user decides not to authorise the payment then a time out message is sent from the wireless computing device to the content server (message 58), which forwards the message to the payment server (message 59). The payment server updates the device database to reflect the fact that no payment was authorised (message 60).

Referring now to Figures 5a to 5h these illustrate the format of the most important messages passed between the wireless computing device and the content server in the above locked data file download scenario. In each of these illustrated message formats the header field contains the identifier of the transmitting unit (either the wireless computing device or the content provider). The header also includes information conventionally held within the headers of packets passed in data networks conforming to industry standards, such as the length of the packet.

In each message the digest field contains the result of a SHA-1 digest that is performed upon the whole of the message for integrity checking. Messages may also be encrypted using standards based public key cryptographic functions, such as AES and digitally signed. This is the asymmetric encryption scheme referred to above for encrypting the whole download package. Both the content provider and the media player are able to encrypt and decrypt messages. The decryption key may be sent within the message as part of the unlock code.

Only additional fields for the illustrated messages will be referred to below.

Figure 5a illustrates message 40 -the request for the media player. It contains a request for the media player 70. If appropriate, message 40 also contains the mobile subscriber international subscriber identity number (MSISDN) 71 for additional verification of the identity of the wireless computing device. This is a unique number assigned to all mobile telephones during Figure 5b illustrates message 43 -the download of the media player to the wireless computing device. This contains the device identifier 72 and the media player 73.

Figure 5c is message 44 -the request for a data file. it contains the device identifier 72 and a request for a data file 74.

Figure 5d is message 49 -the download of the locked data file to the wireless computing device. It contains the locked data file 75, a data file identifier 76, a preview field 77, a purchase prompt field 78 and a lock code field 79.

The preview field, if present, contains a short fragment of the data file in an unlocked format. For instance, for a downloaded music file, 20 seconds of the file may be sent unlocked allowing the user to sample the music before buying.

The purchase prompt field prompts the user to purchase the file. If the user elects to purchase a file, a purchase request message, sent for instance as an SMS message, is sent to the content provider to request the unlock code.

Figure Se is the purchase request message SO. it contains the device identifier 72, the data file identifier 76, the lock code 79 and a purchase request 80.

Figure 5f is the payment information message 53. It contains the data file identifier 76, payment information 81 and a reply to number field 82. The reply to number field allows the content provider to dynamically set the price for a media file, for payment by a premium rate SMS message. For example, newer songs may charged at one rate, whilst older songs are charged at a different rate. It also provides a mechanism for promotional offers and a method to manage pricing segmentation.

The reply to field changes the number that the SMS message reply is sent to.

Figure 5g is the payment authorisation message 54. It contains the device identifier 72 (alternatively or in addition, this could be contained within the header), the data file identifier 76 and payment authorisation 83.

Figure 5h is the unlock code message 57. This contains the data file identifier 76 and an unlock code 84.

Referring now to Figure 6, this illustrates in the form of a flowchart the process of forwarding a data file from a first wireless computing device to another wireless computing device.

At step 90 the first wireless computing device forwards the locked data file to the second wireless computing device. The package contains the locked contents, a lock code and the data file identifier. The package also contains the device identifier of the first wireless computing device. The wireless computing device generates the same form of encrypted download package as that originally downloaded from the content provider.

At step 91 the user at the new wireless computing device can preview the contents of the locked data file as is the case for users downloading a data file from the content provider.

At step 92 the second wireless computing device sends a purchase request to the content provider, which contains the device identifier, the data file identifier, the lock code and the address of the wireless computing device that forwarded the data file.

At step 93 the content provider responds to the purchase request with payment information including the cost of the data file, or a price list if a range of data files are being downloaded. The price list also includes the device identifier, the lock code and the data file identifier. The payment information or the price list may be dynamically updated by the content provider to reflect the value of the data file.

At decision step 94 the user must decide whether or not to authorise the payment. If no payment authorisation is made then the system times out at step 95 and the process ends. Alternatively, the user may authorise the payment at step 96 by sending a message to the content provider, typically in the form of a premium rate SMS message. The payment authorisation will contain the device identifier, the data file identifier and payment authorisation. In response to the payment authorisation the content provider sends the unlock code to the wireless computing device at step 97.

The wireless computing device uses the unlock code to unlock the data file such that it may be opened or played.

At step 98, after payment by the second wireless computing device has been authorised the content provider can make a commission payment to the user associated with the first wireless computing device. This may be by crediting an account associated with the user. The account may either be with the content provider or with the operator of the wireless network.

Figure 7 illustrates the message flows associated with the above data file forwarding scenario. It is assumed that the second wireless computing device has already downloaded the media player from the content provider.

In message 100 the first wireless computing device forwards a locked data file to the second wireless computing device.

In message 101 the user makes a purchase request to the content server, which forwards the request to the payment server. The payment server sends the payment information to the second wireless computing device (message 102).

If the user decides to authorise the payment then message 103 is sent to the content server and forwarded to the payment server. The security server returns the unlock code to the wireless computing device in message 104. The payment server updates the device database (message 105). Alternatively, if the user decides not to authorise the payment then a time out message is sent from the wireless computing device to the content server (message 108), which forwards the message to the payment server. The payment server updates the device database to reflect the fact that no payment was authorised (message 109). If a payment is authorised, then the payment server also updates the device database for the first wireless computing device in message 110.

Referring now to Figures 8a and 8b, these illustrate the format of the most important messages when forwarding the locked data file from a first wireless computing device to a second wireless computing device and the purchase request from the second wireless computing device to the content server in the above forwarding scenario. The other messages passed between the second wireless computing device and the content provider are the same as for the equivalent messages in Figures 5a to 5h. As for Figures 5a to 5h, in each of these illustrated message formats the header field contains the identifier of the transmitting unit (either a wireless computing device or the content provider) and the digest field contains the result of a SHA-1 digest which is performed upon the whole of the message for integrity checking. Only additional fields for the illustrated messages will be referred to below.

Figure 8a is message 100-the forwarding of the locked data file from the first wireless computing device to the second wireless computing device. It contains the locked data file 75, a data file identifier 76, a preview field 77, a purchase prompt field 78, a lock code field 79 and a from device identifier 120 containing the identifier of the wireless computing device which forwards the locked data file 75.

Figure 8b is the purchase request message 103. It contains the device identifier 72, the data file identifier 76, the lock code 79, a purchase request 80 and the from device identifier 120. Sending the from device identifier 120 to the content provider activates the commission process upon authorisation of the payment from the second wireless computing device.

If the second wireless computing device forwards the locked data file to yet another wireless computing device then as well as the forwarding message containing the identifier of the second wireless computing device for commission purposes it may also contain the identifier of the device which initially downloaded the data file from the content provider. Both identifiers are passed to the content provider in the purchase request message. If a further payment is authorised, both the immediate forwarding device and the originally downloading device may be entitled to a commission.

A first wireless computing device may forward a locked data file to a second wireless computing device owned by the same user. Under certain circumstances the content provider may not require a further payment as both are owned by the same user (this may be dependent upon the terms of the copyright licence under which each data file is distributed). If the user has previously registered both wireless computing devices, such that in the device database at the content provider the device identifier for each lists the same user, then when the second wireless computing device sends the purchase request message 103 to the content provider the content provider will recognise that the two wireless computing devices are owned by the same user and can proceed to send the unlock code to the second wireless computing device immediately without requiring a payment authorisation step. In order to prevent abuse, it may be necessary to limit the number of devices that can be registered by each user.

Although embodiments of the present invention have been described above specifically with reference to a wireless network, the invention is not limited to this.

The present invention is also applicable to any other form of network, such as a wired connection to the Internet, in which data is downloaded to a wired computing device.

Other objects and advantages of the present invention will be readily apparent to the appropriately skilled person, without departing from the scope of the appended claims.

Claims

CLAIMS

1. A method of transferring data files in a network, comprising: requesting a data file from a content provider at a computing device; transmitting a locked data file from the content provider to the computing device; authorising a payment to the content provider; transmitting an unlock code to the computing device in response to said payment; and unlocking the locked data file at the computing device such that the locked data file can be opened on the computing device.

2. A method according to claim 1, wherein said network comprises a wireless network and said computing device comprises a wireless computing device.

3. A method according to claim I or claim 2, wherein transmitting the unlock code to the computing device comprises transmitting the unlock code from the content provider to the computing device.

4. A method according to any one of the preceding claims, further comprising receiving at the computing device a lock code, the lock code being arranged to prevent the locked data file being opened on the computing device without the unlock code.

5. A method according to any one of the preceding claims, further comprising receiving at the computing device payment information which indicates the value of the payment to be authorised to the content provider in order to receive the unlock code in response to said payment.

6. A method according to any one of the preceding claims, further comprising: assigning a data file identifier at the content provider to the locked data file; and receiving the data file identifier at the computing device.

7. A method according to claim 6, further comprising providing the data file identifier from the computing device to the content provider when authorising the payment to the content provider, such that the content provider can reconcile the payment to the locked data file.

8. A method according to claim 6 or claim 7, further comprising assigning a device identifier to the computing device.

9. A method according to claim 8, further comprising maintaining a device database, the device database comprising a plurality of records, each record comprising an entry for a device identifier of a respective computing devices.

10. A method according to claim 9, further comprising the content provider updating the device database record for a device identifier to indicate that the computing device has received a locked data file.

11. A method according to claim 9 or claim 10, further comprising updating the device database record for a device identifier to indicate that the computing device has authorised a payment to the content provider.

12. A method according to any one of claims 9 to 11, further comprising updating the device database record for a device identifier to indicate that the computing device has received the unlock code from the content provider.

13. A method according to any one of claims 8 to 12, further comprising receiving at the computing device a media player from the content provider, the media player being adapted to receive the unlock code from the content provider and unlock the locked data file, wherein receiving the media player from the content provider assigns the device identifier to the computing device.

14. A method according to claim 13, further comprising: transmitting information identifying the user of the computing device from the computing device to the content provider; and updating the device database record for the device identifier with the information identifying the user of the computing device.

15. A method according to any one of claims 8 to 14, wherein the unlock code is dependent upon the device identifier and the data file identifier, such that only the computing device assigned that device identifier can unlock the locked data file assigned that data file identifier.

16. A method according to any one of the preceding claims, further comprising receiving a prompt message to authorise the payment to the content provider at the computing device after the computing device has received the locked data file.

17. A method according to claim 16, wherein authorising the payment to the content provider comprises transmitting a payment message to the content provider from the computing device in response to the prompt message.

18. A method according to claim 16, wherein if a user associated with the computing device chooses not to authorise the payment to the content provider then the method comprises transmitting a time out message to the content provider from the computing device at a predetermined period of time after the prompt message.

19. A method according to claim 16 when dependent upon claim 9, further comprising updating the device database record for the device identifier to indicate that the computing device has not authorised a payment to the content provider.

20. A method according to any one of the preceding claims, wherein the content provider further comprises a data file database, the method further comprising accessing the data file database and selecting the locked data file at the computing device.

21. A method according to any one of the preceding claims, wherein authorising a payment to the content provider comprises sending an SMS message from the computing device to the content provider.

22. A method according to claim 21, wherein the SMS message comprises a premium rate SMS message.

23. A method according to any one of claims I to 20, wherein authorising a payment to the content provider comprises authorising a payment from a debit or credit card account associated with a user of the computing device to the content provider.

24. A method according to any one of the preceding claims, further comprising paying a royalty fee from the content provider to the copyright holder of the locked data file in response to said payment.

25. A method according to any one of the preceding claims, further comprising transmitting the locked data file from a first computing device to a second computing device.

26. A method according to claim 25 when dependent upon claim 8, further comprising transmitting the device identifier of the first computing device from the first computing device to the second computing device.

27. A method according to claim 26, when dependent upon claim 14, further comprising checking the records in the device database for the device identifiers of the first and second computing devices to determine whether the information identifying the users of the computing devices is the same.

28. A method according to claim 27, further comprising: receiving an unlock code at the second computing device from the content provider; and unlocking the locked data file at the second computing device such that the locked data file can be opened on the second computing device.

29. A method according to claim 28, further comprising: authonsing a payment from the second computing device to the content provider; and transmitting the unlock code to the second computing device in response to said payment.

30. A method according to claim 29, further comprising receiving a commission payment from the content provider at the first computing device in response to said payment from the second computing device.

31. A method according to any one of the preceding claims, further comprising: assigning a content provider identifier to each of a plurality of content providers; and receiving the content provider identifier at the computing device.

32. A method according to any one of the preceding claims, further comprising: transmitting a data file to a content provider from a first computing device; and making said data file available as a locked data file at the content provider for transmission to other computing devices.

33. A method according to claim 32 when dependent upon claim 14, further comprising paying a royalty payment from the content provider to a user associated with the first computing device in response to a payment authorised by another computing device.

34. A method according to any one of the preceding claims, further comprising: transmitting a playlist to a content provider from a first computing device; and making data files contained within the playlist available as locked data files at the content provider for transmission to other computing devices.

35. A method according to claim 34 when dependent upon claim 14, further comprising paying a commission payment from the content provider to a user associated with the first computing device in response to a payment authorised by another computing device.

36. A carrier medium carrying computer readable code for controlling a computer to carry out the method of any one of claims I to 35.

37. A computer apparatus for transferring data files in a network, the apparatus comprisiflg a program memory storing processor readable instructions; and a processor configured to read and execute instructions stored in said program memory; wherein the processor readable instructions comprise instructions controlling the processor to carry out the method of any one of claims I to 35.

38. A method of receiving data files at a computing device, comprising: requesting a data file from a content provider; receiving a locked data file at the computing device from the content provider; authorising a payment to the content provider; receiving an unlock code at the computing device in response to said payment; and unlocking the locked data file such that the locked data file can be opened on the computing device.

39. A method according to claim 38, wherein said network comprises a wireless network and said computing device comprises a wireless computing device.

40. A method according to claim 38 or claim 39, wherein receiving the unlock code at the computing device comprises receiving the unlock code from the content provider at the computing device.

41. A method according to any one of claims 35 to 40, further comprising receiving at the computing device a lock code, the lock code being arranged to prevent the locked data file being opened on the computing device without the unlock code.

42. A method according to any one claims 28 to 41, further comprising receiving at the computing device payment information which indicates the value of the payment to be authorised to the content provider in order to receive the unlock code in response to said payment.

43. A method according to any one of claims 38 to 42, further comprising receiving a data file identifier assigned to the locked data file at the computing device.

44. A method according to claim 43, further comprising providing the data file identifier from the computing device to the content provider when authorising the payment to the content provider, such that the content provider can reconcile the payment to the locked data file.

45. A method according to claim 43 or claim 44, further comprising receiving a device identifier at the computing device, the device identifier identifying the computing device.

46. A method according to claim 45, further comprising receiving at the computing device a media player from the content provider, the media player being adapted to receive the unlock code from the content provider and unlock the locked data file, wherein receiving the media player from the content provider assigns the device identifier to the computing device.

47. A method according to claim 46, further comprising transmitting information identifying the user of the computing device from the computing device to the content provider.

48. A method according to any one of claims 45 to 47, wherein the unlock code is dependent upon the device identifier and the data file identifier, such that only the computing device assigned that device identifier can unlock the locked data file assigned that data file identifier.

49. A method according to any one of claims 38 to 48, further comprising receiving a prompt message to authorise the payment to the content provider at the computing device after the computing device has received the locked data file.

50. A method according to claim 49, wherein authorising the payment to the content provider comprises transmitting a payment message to the content provider from the computing device in response to the prompt message.

51. A method according to claim 49, wherein if a user associated with the computing device chooses not to authorise the payment to the content provider then the method comprises transmitting a time out message to the content provider from the computing device at a predetermined period of time after the prompt message.

52. A method according to any one of claims 38 to 51, wherein the content provider further comprises a data file database, the method further comprising accessing the data file database and selecting the locked data file at the computing device.

53. A method according to any one of claims 38 to 52, wherein authorising a payment to the content provider comprises sending an SMS message from the computing device to the content provider.

54. A method according to claim 53, wherein the SMS message comprises a premium rate SMS message.

55. A method according to any one of claims 38 to 52, wherein authorising a payment to the content provider comprises authorising a payment from a debit or credit card account associated with a user of the computing device to the content provider.

56. A method according to any one of claims 38 to 55, further comprising transmitting the locked data file from a first computing device to a second computing device.

57. A method according to claim 56, when dependent upon claim 45, further comprising transmitting the device identifier of the first computing device from the first computing device to the second computing device.

58. A method according to claim 57, further comprising: receiving an unlock code at the second computing device from the content provider; and unlocking the locked data file at the second computing device such that the locked data file can be opened on the second computing device.

59. A method according to claim 58, further comprising: authorising a payment from the second computing device to the content provider; and receiving the unlock code at the second computing device in response to said payment.

60. A method according to claim 59, further comprising receiving a commission payment from the content provider at the first computing device in response to said payment from the second computing device.

61. A method according to any one of claims 28 to 60, further comprising receiving a content provider identifier at the computing device.

62. A method according to any one of claims 38 to 61, further comprising transmitting a data file to a content provider from a first computing device such that the content provider can make said data file available as a locked data file at the content provider for transmission to other computing devices.

63. A method according to claim 62 when dependent upon claim 47, further comprising receiving a royalty payment from the content provider to a user associated with the first computing device in response to a payment authorised by another computing device.

64. A method according to any one of claims 38 to 63, further comprising transmitting a playlist to a content provider from a first computing device such that the content provider can make data files contained within the playlist available as locked data files at the content provider for transmission to other computing devices.

65. A method according to claim 64 when dependent upon claim 47, further comprising paying a commission payment from the content provider to a user associated with the first computing device in response to a payment authorised by another computing device.

66. A carrier medium carrying computer readable code for controlling a computer to carry out the method of any one of claims 38 to 65.

67. A computer apparatus for receiving data files at a computing device, the apparatus comprising: a program memory storing processor readable instructions; and a processor configured to read and execute instructions stored in said program memory; wherein the processor readable instructions comprise instructions controlling the processor to carry out the method of any one of claims 38 to 65.

68. A method of transmitting data files from a content provider, comprising: receiving a request for a data file at the content provider from a computing device; transmitting a locked data file to the computing device; receiving notification that a payment to the content provider has been authorised; and transmitting an unlock code to the computing device in response to said payment such that the computing device can unlock the locked data file open the locked data file on the computing device.

69. A method according to claim 68, wherein said network comprises a wireless network and said computing device comprises a wireless computing device.

71. A method according to claim 68 or claim 69, wherein transmitting the unlock code to the computing device comprises transmitting the unlock code from the content provider to the computing device.

71. A method according to any one of claims 68 to 70, further comprising transmitting to the computing device a lock code, the lock code being arranged to prevent the locked data file being opened on the computing device without the unlock code.

72. A method according to any one of claims 68 to 71, further comprising transmitting to the computing device payment information which indicates the value of the payment to be authorised to the content provider in order for the unlock code to be transmitted in response to said payment.

73. A method according to any one of claims 68 to 72, further comprising: assigning a data file identifier at the content provider to the locked data file; and transmitting the data file identifier to the computing device.

74. A method according to claim 73, further comprising receiving the data file identifier from the computing device when receiving notification of the payment authorisation, and reconciling the payment to the locked data file at the content provider.

75. A method according to claim 73 or claim 74, further comprising assigning a device identifier to the computing device.

76. A method according to claim 75, further comprising maintaining a device database, the device database comprising a plurality of records, each record comprising an entry for the device identifier of each of a plurality of computing devices.

77. A method according to claim 76, further comprising the content provider updating the device database record for a device identifier to indicate that the computing device has received a locked data file.

78. A method according to claim 76 or claim 77, further comprising updating the device database record for a device identifier to indicate that the computing device has authorised a payment to the content provider.

79. A method according to any one of claims 76 to 78, further comprising updating the device database record for a device identifier to indicate that the computing device has received the unlock code from the content provider.

80. A method according to any one of claims 75 to 79, further comprising transmitting to the computing device a media player from the content provider, the media player being adapted to receive the unlock code from the content provider and unlock the locked data file, wherein transmitting the media player to the computing device assigns the device identifier to the computing device.

81. A method according to claim 80, further comprising: receiving information identifying the user of the computing device from the computing device at the content provider; and updating the device database record for the device identifier with the information identifying the user of the computing device.

82. A method according to any one of claims 75 to 81, wherein the unlock code is dependent upon the device identifier and the data file identifier, such that only the computing device assigned that device identifier can unlock the locked data file assigned that data file identifier.

83. A method according to any one of claims 68 to 82, further comprising transmitting a prompt message to authorise the payment to the content provider to the computing device after transmitting the locked data file to the computing device.

84. A method according to claim 83, wherein receiving notification that the payment to the content provider has been authorised comprises receiving a payment message at the content provider from the computing device in response to the prompt message.

85. A method according to claim 83, wherein if a user associated with the computing device chooses not to authorise the payment to the content provider then the method comprises receiving a time out message at the content provider from the computing device at a predetermined period of time after the prompt message.

86. A method according to claim 85 when dependent upon claim 76, further comprising updating the device database record for the device identifier to indicate that the computing device has not authorised a payment to the content provider.

87. A method according to any one of claims 68 to 86, wherein the content provider further comprises a data file database.

88. A method according to any one of claims 68 to 87, wherein receiving notification that a payment to the content provider has been authorised comprises receiving an SMS message from the computing device at the content provider.

89. A method according to claim 88, wherein the SMS message comprises a premium rate SMS message.

90. A method according to any one of claims 68 to 87, wherein receiving notification that a payment to the content provider has been authorised comprises receiving a payment at the content provider from a debit or credit card account associated with a user of the computing device.

91. A method according to any one of claims 68 to 90, further comprising paying a royalty fee from the content provider to the copyright holder of the locked data file in response to said payment.

92. A method according to claim 81 or any claim dependent thereon, further comprising checking the records in the device database for the device identifiers of first and second computing devices to determine whether the information identifying the users of the computing devices is the same.

93. A method according to claim 92, further comprising: transmitting an unlock code to the second computing device from the content provider such that the second computing device can unlock the locked data file and open the locked data file on the second computing device.

94. A method according to claim 93, further comprising: receiving notification that a payment to the content provider has been authorised by the second computing device; and transmitting the unlock code to the second computing device in response to said payment.

95. A method according to claim 94, further comprising paying a commission payment from the content provider to the first computing device in response to said payment from the second computing device.

96. A method according to any one of claims 68 to 95, further comprising: assigning a content provider identifier to each of a plurality of content providers; and transmitting the content provider identifier to the computing device.

97. A method according to any one of claims 68 to 96, further comprising: receiving a data file at a content provider from a first computing device; and making said data file available as a locked data file at the content provider for transmission to other computing devices.

98. A method according to claim 97 when dependent upon claim 81, further comprising paying a royalty payment from the content provider to a user associated with the first computing device in response to a payment authorised by another computing device.

99. A method according to any one of claims 68 to 98, further comprising: receiving a playlist at a content provider from a first computing device; and making data files contained within the playlist available as locked data files at the content provider for transmission to other computing devices.

100. A method according to claim 99 when dependent upon claim 81, further comprising paying a commission payment from the content provider to a user associated with the first computing device in response to a payment authorised by another computing device.

101. A carrier medium carrying computer readable code for controlling a computer to carry out the method of any one of claims 68 to 100.

102. A computer apparatus for transmitting data files from a content provider, the apparatus comprising: a program memory storing processor readable instructions; and a processor configured to read and execute instructions stored in said program memoiy wherein the processor readable instructions comprise instructions controlling the processor to carry out the method of any one of claims 68 to 100.

103. A system for transferring data files in network, comprising: a computing device comprising means to request a data file from a content provider; a content provider comprising means to transmit a locked data file to the computing device; and means to authorise a payment to the content provider; wherein the network further comprises means to transmit an unlock code to the computing device in response to said payment and the computing device further comprises means to unlock the locked data file such that the locked data file can be opened on the computing device.

104. A computing device, comprising: means to request a data file from a content provider; means to receive a locked data file at the computing device from the content provider; means to authorise a payment to the content provider; means to receive an unlock code at the computing device in response to said payment; and means to unlock the locked data file such that the locked data file can be opened on the computing device.

105. A content provider apparatus, comprising: means to receive a request for a data file at the content provider from a computing device; means to transmit a locked data file to the computing device; means to receive notification that a payment to the content provider has been authorised; and means to transmit an unlock code to the computing device in response to said payment such that the computing device can unlock the locked data file and open the locked data file on the computing device.

106. A method according to any one of claims 1 to 35, further comprising transmitting from the content provider to the computing device a preview field, the preview field containing a portion of the locked data file in an unlocked format.

107. A method according to any one of claims 38 to 65, further comprising receiving at the computing device a preview field, the preview field containing a portion of the locked data file in an unlocked format.

108. A method according to any one of claims 68 to 100, further comprising transmitting to the computing device a preview field, the preview field containing a portion of the locked data file in an unlockedformat.