Secure storage system and method

FIELD OF THE INVENTION

[0001] The present invention generally relates to a secure storage system and method for securely storing files in encrypted form and for allowing a user access to the files via the Internet.

BACKGROUND OF THE INVENTION

[0002] With the prevalent use of computers in the business world, heavy reliance is placed on the security of data and the easy availability of such data.

[0003] With the growth of the Internet it has been realized that it is possible to provide storage on a server which is available to a user over the Internet. Users are thus able to pay for storage space which they can access from anywhere via the Internet. One major issue with such a system is, however, inherent security of such a system.

[0004] An object of the present invention is to provide a secure storage system and method which provides for secure access to files in a storage area within the requirement for security software on the user's computer.

SUMMARY OF THE INVENTION

[0005] In accordance with one aspect, the present invention provides a secure storage system and method in which encrypted information, e.g. data files, program files, or any other type of information can be stored in a secure storage area which is accessible over the Internet. User specific user interface code is generated and stored at a location which is accessible to a user over the Internet. The user specific user interface code is user specific since it requires the entry of a user password during execution on a computer. During execution of the user specific user interface code, and upon entry of the correct user password, the interface provides access to the encrypted information in the storage area over the Internet.

[0006] Thus in accordance with this aspect of the present invention, a user is able to gain access to encrypted information, i.e. files, by downloading the user specific user interface code, executing the code, and entering a correct user specific password. This will activate the code and allow the user access to the encrypted files. Thus this aspect of the present invention is secure since the user interface code is required in order to access the secure storage area. This is available to a user using any computer connected to the Internet and can be downloaded. Security is assured by requiring a user password in order for the interface code to execute.

[0007] The encrypted files can be stored on the storage area using any means by which secure access can be obtained to the storage area. In one embodiment a similar user interface to the downloadable user specific user interface is provided on a user's own computer, i.e. a computer that they usually use and which is configured for their own use. Thus in this way the storage area acts as a means by which they can securely back up their files. A user interface can be provided to allow access to the storage area from the user's usual computer to allow them to upload encrypted files for safe storage in case of loss or theft of the user's usual computer. It is when the user's usual computer is lost or stolen that the present invention is particularly useful. Since the user has lost their usual means of accessing the storage area securely, they require another way of accessing the encrypted files in the storage area securely. In order to do this, a user can make use of any other computer connected to the Internet to connect to a site holding the user specific user interface code and download the code onto the user's temporary computer. By entry of the user's password, the user specific user interface is activated to allow the user access to the encrypted files in the storage area. In a preferred embodiment, the user specific user interface provides for conventional file manipulation, i.e. uploading and downloading of files, and deletion of files in the storage area. Files which are uploaded are uploaded in encrypted form and files which are downloaded can be automatically decrypted, or stored in encrypted form for later decryption.

[0008] In a preferred embodiment of the present invention, the method of encryption uses the user's password as the encryption key. Thus the encrypted files are user specifically encrypted. In this preferred embodiment, symmetric key encryption is used thereby allowing decryption using the same user password. Thus the user password used to activate the user specific user interface code can also be used for the decryption of the encrypted files. This decryption can be selected by the user when implementing the user interface to take place automatically upon download of files. Alternatively, the user interface can allow later decryption of downloaded files which are stored on the user's temporary computer.

[0009] When a user wishes to take advantage of this secure storage system, they can register for the service. The registration data is received at a registration server whereupon a storage area is assigned for the user and user specific user interface code is generated for the user. The data required for registration includes the user password and security information to access the secure area. In a preferred embodiment the accessing is carried out using the file transfer protocol (FTP). In this case the information required for secure access to the storage area is the location of the storage area, the user name, and a password. This password is different to the password for activating the user specific user interface and for decrypting the files. It can, however, be the same password but it performs a different function. The registration data will also need to include Internet service provider data which includes the telephone number to dial up the Internet service provider, and the log on data to log onto the Internet service provider. In order to avoid users having to have their own Internet service provider, the service can include its own Internet service provider to provide access to the secure storage areas. The log in information for the Internet service provider, i.e. the user name and password, can be the same as that used for secure FTP access to the storage area.

[0010] One method by which the registration process can be carried out is by installation of software onto the user's usual computer. The installation process can include an authentication process to ensure that the software is a legitimate copy purchased from the service provider for registration purposes. During the installation process the user can be asked to enter the necessary registration information. The software can then automatically connected to the registration server to perform the registration process. This will set up the secure storage area for the user and will cause the generation of the user specific user interface. The software installed by the user will also provide the user with a user interface to their secure storage area for secure back up of data in the storage area.

[0011] When a user wishes to access their secure storage area from another computer, e.g. when their usual computer has been lost or stolen, or when they are away from their usual computer, the downloaded user specific user interface is installed on the user's temporary computer. If a user is only temporarily using the computer, it is desirable that the user specific user interface code and any data downloaded onto the user's temporary computer be deleted. In one embodiment of the present invention the user specific user interface code includes the ability to delete itself and/or any data files downloaded onto the user's temporary computer. A user can select to implement this feature when the user specific user interface code terminates execution, i.e. the application is closed. The deletion performed is a secure deletion by overwriting of the storage area on the hard disk to ensure that the code and/or the data can never be read following deletion.

[0012] In one embodiment of the present invention, for ease of use, when the service is set up for a user, a web page is generated in the storage area. A user will thus know the location of the storage area and can thus point their web browser to this area in order to access the web page. The web page includes a link to the location of the user specific user interface code so that this can be automatically downloaded by clicking on the link.

[0013] In one embodiment of the present invention, the size of the storage area available to the user is of a predetermined limited size. Thus in one embodiment of the present invention the user specific user interface includes an indicator of the available capacity in the storage area. This can be achieved by monitoring the uploading of files into the storage area the deletion of files in the storage area. Conventional downloading of files need not be monitored since the downloading will not remove the original copy of the file in the storage area. The available capacity in the storage area can thus be determined as files are moved to and from the storage area.

[0014] It can be seen that since the present invention is implemented by a network of computers networked via the Internet, the present invention encompasses the execution of code on a computer used by a user, a computer performing the service generation process, i.e. the setting up of the storage area and the generation of the user specific user interface code, and the computer providing the storage area. The present invention thus encompasses any such computer used in the implementation of the present invention.

[0015] The present invention is preferably implemented on computers executing computer code. Computer code can be provided to the computers by any suitable carrier medium. A suitable carrier medium can be a storage medium such as a floppy disk, hard disk, CD-ROM, or programmable memory device, or a transient medium such as an electrical, optical, microwave, or acoustic signal (e.g. a signal carrying computer code over a computer network such as a TCP/IP signal carrying computer code over the Internet).

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a schematic diagram of the secure storage system in accordance with an embodiment of the present invention;

[0017]FIG. 2 is a schematic diagram of the user's laptop computer in the embodiment of FIG. 1;

[0018]FIG. 3 is a schematic diagram of the vault server in the embodiment of FIG. 1;

[0019]FIG. 4 is a flow diagram illustrating the insulation and registration process in accordance with an embodiment of the present invention;

[0020]FIG. 5 is a schematic diagram of the user interface in accordance with an embodiment of the present invention showing selection of a file for upload to the secure storage area;

[0021]FIG. 6 is a schematic diagram of the user interface following the uploading of the file to the secure storage area showing the content of one directory of the storage area in accordance with an embodiment of the present invention;

[0022]FIG. 7 is a flow diagram illustrating the operation of the user interface in accordance with an embodiment of the present invention;

[0023]FIG. 8 is a flow diagram illustrating the process for downloading and executing the user interface on a temporary computer by a user; and

[0024]FIG. 9 is a schematic diagram of the user's temporary computer after download of an installation of the user specific user interface code.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0025]FIG. 1 is a schematic diagram illustrating in outline an embodiment of the present invention which will be described in more detail hereinafter in which a user usually uses a laptop <b>1</b> as their normal computer. The laptop <b>1</b> has a means by which it can access the Internet, e.g. a network card, or modem. A vault server <b>3</b> is available over the Internet and hosts the secure storage service. In this embodiment a user also has access temporarily to another computer <b>4</b>, e.g. when their laptop is lost, stolen, or breaks down, or when they are temporarily away from their computer <b>1</b>. The user's temporary computer <b>4</b> also has means by which it can connect to the Internet <b>2</b>, e.g. network card, or modem for dial-up access.

[0026]FIG. 2 is a schematic diagram of the user's laptop computer following installation of the secure storage application for normal use by the user to access the service hosted by the vault server <b>3</b>.

[0027] The computer <b>1</b> comprises a network interface <b>10</b> such as a network card for local area network access, a digital subscriber line adapter, or a modem for dial-up access. A hard disk <b>18</b> stores files and data used by the user and by the application. It stores the secure storage application code, files used by the user, and application data files used by the secure storage application. The user's files can comprise any files such as Microsoft Word documents, presentation files, spreadsheets, or image files. The application data files store the data securely and secretly to avoid unauthorized access. The data includes data required to access the network. Where the network interface <b>10</b> is a modem, dialler data is needed including telephone number and user name and password for accessing an Internet service provider. In order to access the storage area, server access data is stored. This includes the host name of the server hosting the secure storage area and the user name and password for accessing the secure storage area. In this embodiment of the present invention, these comprise parameters used by the file transfer protocol (FTP) module for FTP transfer of data to and from the storage area.

[0028] The computer <b>1</b> also includes a pointing device <b>13</b> such as a mouse to allow a user to interface to the computer. A display <b>11</b> is provided to provide a visual output to allow the computer to interface to the user. Further, a keyboard <b>12</b> is provided to allow for user interface. A data memory <b>16</b> comprising volatile memory, i.e. RAM, stores data used by the application during execution. This data includes the user password, the server address data, the dialler data, and the vault data. The vault data includes all information on the configuration of the secure storage area (termed “the vault”). This includes the available capacity, the folders or directory names and file names, sizes and locations. This information is held in volatile memory since it is determined every time the user's interface is generated by accessing the storage area (the vault).

[0029] The computer <b>1</b> also includes a program memory <b>15</b> which comprises volatile memory storing program code which is used by a processor <b>14</b> to execute the application. The application code stored in the program memory <b>15</b> can be considered in this embodiment to be comprised of six functional code modules: interface code for generating the user interface, dialler code for controlling the modem to connect to the Internet, FTP code for performing FTP commands and FTP transfers of files, encryption code for performing encryption and decryption of files using the user password as the key for both encryption and decryption, file manipulation code for allowing files to be manipulated both locally and remotely in the secure storage area, and capacity meter code for dynamically determining the current capacity in the secure storage area and for generating capacity information for use by the interface code in generating the user interface.

[0030] All the components of the computer <b>1</b> are interlinked by the control and data bus <b>17</b>.

[0031] The structure of the vault server <b>3</b> will now be described with reference to FIG. 3. In this embodiment of the present invention the vault server <b>3</b> performs both the registration process and the secure storage area service. However, it is possible for these two functions to be performed by different servers.

[0032] In this embodiment of the present invention a storage device <b>23</b> is provided for storing users' directories which comprise the secure storage areas for users. Each user is assigned a user's directory into which is stored an index.html file <b>25</b> to act as a web interface. The user's directory also includes sub-directories or folders for the storage of encrypted files by the user. In this embodiment there are six folders or sub-directories headed: Documents, Presentations, Contracts, X Files, Letters and Pictures.

[0033] The storage device <b>23</b> also contains in this embodiment the remote vault interface installer code <b>24</b> (i.e. the user specific user interface code).

[0034] A file transfer protocol (FTP) server <b>22</b> is provided which is accessible over the Internet for controlling access to the folders or sub-directories within the user's directory. The FTP server <b>22</b> provides secure access since, as is well known for FTP servers, a user name and password is required to access a directory.

[0035] A web server <b>20</b> is also provided for accessing the index.html file <b>25</b> in each user's directory to provide a web interface. The index.html file <b>25</b> can be accessed by a web browser executed on the user's temporary computer in order to enable them to select to download the remote vault interface installer code <b>24</b> in the storage device <b>23</b>.

[0036] A vault installer application <b>21</b> is also provided for performing the registration process. The vault installer application <b>21</b> will receive registration parameters from a user during the installation of the secure storage application. The vault installer application <b>21</b> will then set up the storage area by creating a user's directory and a number of folders or sub-directories with default labels. Also, the vault installer application <b>21</b> will generate the remote vault interface installer code <b>24</b> (i.e. the user specific user interface code).

[0037] The operation of the secure storage application will now be described with reference to FIGS. <b>4</b> to <b>7</b>.

[0038]FIG. 4 is a flow diagram illustrating the installation of the secure storage application and the registration process for registration of a user for the secure storage service.

[0039] A user is provided with a secure storage application installation package and in step S<b>1</b> this is loaded into the computer, e.g. on a CD-ROM or floppy disk. The installation application generates a user interface (step S<b>2</b>). The user interface requires the input of registration parameters. These include:

[0040] 1. A user password selected and input by a user.

[0041] 2. Internet service provider (ISP) log in data. This data includes the telephone number for dial-up access, the user name and password for connection to the ISP. In order to avoid a user having to already have (or find) an ISP, the service can automatically provide an ISP for accessing the service. Thus this data can be set to the default ISP log in data and need not be modified or entered by a user.

[0042] 3. Vault folder names. The names of the folders in the vault can be chosen by a user. For example, in this embodiment the user can select the folders to be: Documents, Presentations, Contracts, X Files, Letters and Pictures. After the data is entered by the user using the user interface (step S<b>2</b>) the application determines whether there is already a transmission control protocol/Internet protocol (TCP/IP) connection, i.e. an Internet connection (step S<b>4</b>). If so, the installation application makes a connection to the vault server <b>3</b>, and specifically to the vault installer application <b>21</b> (step S<b>6</b>). If there is no TCP/IP connection, i.e. no Internet connection (step S<b>4</b>) the dialler code controls the modem to use the ISP log in data to dial-up the ISP and log on (step S<b>5</b>). Once a TCP/IP connection is made to the ISP, a connection is then made to the vault server <b>3</b> (step S<b>6</b>) and more specifically a connection is made to the vault installer application <b>21</b>. The vault installer application <b>21</b> in the vault server <b>3</b> then creates the password protected users' directories with the input folder names. Also, the vault installer application <b>21</b> generates the remote vault interface installer code <b>24</b> and stores it in the storage device <b>23</b>. Further, the index.html file <b>25</b> is generated and stored in the user's directory. The index.html file comprises a standard html template with a link to the user's specific remote vault interface installer code (step S<b>7</b>). Thus at this point a user has been registered for the service and the vault server <b>3</b> is configured for the service.

[0043] The installation application then installs the vault interface application onto the user's laptop computer <b>1</b> with the password, ISP log in data, initial capacity and vault folder names (step S<b>8</b>). The vault interface application then executes to generate the user interface (step S<b>9</b>). The vault interface will use volatile data stored in the data memory <b>16</b>.

[0044]FIG. 5 is a schematic diagram of the user interface. The user interface is comprised of two parts: a vault interface showing data related to the vault (i.e. the remote storage area) and an area <b>31</b> showing parameters related to local storage on a user's laptop computer <b>1</b>. As can be seen in FIG. 5, in this embodiment the vault display <b>30</b> displays six folders <b>32</b> labelled Documents, Presentations, Contracts, X Files, Letters and Pictures, respectively. Also there is shown a capacity meter <b>34</b> indicating the storage capacity left in the vault. In the area <b>31</b> showing the parameters related to local storage, the local drive selected is indicated, which in this case is C:. Also the local folder selected is indicated which in this case comprises Office. Files within the selected folder can be selected using the pointer <b>33</b> and in this case the file Picture 5.JPG has been selected. Using the conventional Microsoft Windows (trade mark) operation this file can be dragged and dropped into the Pictures folder. This operation is illustrated in FIG. 6 which shows the interface after the file Picture 5.JPG has been dragged and dropped into the Pictures folder. The pointer <b>33</b> has been used to open the folder Pictures to display a window <b>35</b> showing the contents in the folder. As can be seen the file Picture <b>5</b>.JPG has been copied or uploaded to the vault. Since a file has been uploaded to the vault, the capacity meter <b>34</b> has been updated to show that the capacity available in the vault has decreased. The operation of the vault interface, i.e. the user interface will now be described in more detail with reference to the flow diagram of FIG. 7.

[0045] Once the application is opened (step S<b>20</b>) a log in window is displayed to allow a user to enter their password. Preferably the password does not simply comprise a password but rather a pass phrase. This increases the number of characters, thus increasing the level of security. A log in validation occurs (step S<b>22</b>). If it is determined that the entered password is invalid an invalid log in message is displayed (step S<b>23</b>). If this is the third unsuccessful log in attempt (step S<b>24</b>) the application is closed (step S<b>25</b>). If not, the log in process returns to display the log in window again (step S<b>21</b>).

[0046] Once a user has successfully logged in by entering their password (step S<b>22</b>) the application determines whether there is a TCP/IP connection to the Internet (step S<b>26</b>). This may be because the user is already connected to an ISP via their modem, or because they have a local area network connection. If a TCP/IP connection is already available (step S<b>26</b>), the FTP code in the application uses the FTP data to connect it to the FTP server <b>22</b> in the vault server <b>3</b> to read the vault data, i.e. the user's directory structure (folder names and file names and sizes) to enable the application to generate the vault interface (step S<b>28</b>). If the application does not detect a TCP/IP connection (step S<b>26</b>), the dialler code in the application controls the modem to use the ISP log in data to dial-up and connect to the ISP (step S<b>27</b>). Once a TCP/IP connection is made to the ISP (step S<b>27</b>) vault data can be read from the vault server <b>3</b> by the FTP code in the application making an FTP connection to the FTP server <b>22</b> in the vault server <b>3</b>. The vault interface can then be generated using the vault data. Thus the application initially connects to the vault server in order to determine the correct vault structure to generate a correct vault interface. This is important since, as will be described in more detail hereinafter, it is possible for a user to use a temporary computer in order to access the vault and modify the content of the vault using a different computer. If the vault application on the user's laptop computer <b>1</b> did not connect each time it executed, it would have out-of-date information on the vault, i.e. it would not be synchronized. When the vault interface is generated as illustrated in FIG. 5, a user can select to send or upload files to the vault, to retrieve or download files from the vault, to delete files in the vault, or to move files within the vault from folder to folder (step S<b>29</b>). This can be performed simply by conventional dragging and dropping operations as illustrated and described with reference to FIGS. 5 and 6. If a user makes such a selection, if files are to be sent or uploaded to the vault (step S<b>31</b>) the application determines whether the selected file or files are encrypted (step S<b>32</b>). If not, the encryption code within the application uses the password as an encryption key to perform symmetric key encryption using Blowfish 448 bit encryption. Before an encrypted file is uploaded to the vaults, its file size is compared to the capacity available in the vault as determined by the capacity data (step S<b>34</b>). If the vault has insufficient capacity, a warning is displayed (step S<b>35</b>) which can include information informing the user how to purchase more storage space from the service provider. The process will then return to step S<b>29</b> to await another selection by a user. If there is sufficient capacity in the vault to store the selected encrypted file or files (step S<b>34</b>) or if a user did not select to send (upload) files to the vault, FTP instructions are sent to the FTP server <b>22</b> in the vault server <b>3</b> to perform the selected file transaction (step S<b>36</b>). If the user selected to upload a file to the vault, the type of FTP instruction (step S<b>37</b>) is the upload instruction together with the file and this causes the uploading of the files to the selected folder in the storage device (step S<b>38</b>). If the selection was the deletion of a file in the vault, the type of FTP instruction (step S<b>37</b>) is a deletion and the selected file is deleted in the selected folder in the storage device (step S<b>39</b>). If the user selected to transfer a file between folders, the type of FTP instruction (step S<b>37</b>) is a move instruction which causes the transference of file between folders in the storage device (step S<b>40</b>). If a user selected to download a file from the vault, the type of FTP instructions (step S<b>37</b>) is a download instruction and this causes the file to be downloaded from the selected folder in the storage device to the user's laptop computer <b>1</b> (step S<b>41</b>). A window is then displayed in the vault interface to allow a user to select whether or not to decrypt the files downloaded (step S<b>42</b>). If a user selects to decrypt the files (step S<b>43</b>) the user's password is used as the key for decryption of the selected downloaded files (step S<b>44</b>).

[0047] After having performed either the upload, deletion, moving, or downloading of files, the vault data stored in the user's laptop computer <b>1</b> is updated and this is used to update the vault interface (step S<b>45</b>). In this way the displayed vault interface reflects the content of the vault, i.e. the content of the secure storage area. The updating comprises the updating of the names and sizes of files in the various folders. Also the capacity meter must be updated based on any uploaded or deleted files which changes the capacity available for storage of files in the vault.

[0048] It can thus be seen from the embodiment described hereinabove, that a user can register for the secure storage service and can securely store data on a remote storage device in encrypted form which is only accessible using the vault interface.

[0049] So far accessing of the secure storage area has only been described with reference to the application code stored on the user's usual computer. Whilst this provides a useful secure back-up service, this embodiment of the present invention also provides a far more useful service for secure back-up which does not require original software and which can be accessed from anywhere which provides Internet access. The method of accessing the secure storage area, i.e. the vault without using the user's laptop computer will now be described with reference to FIGS. 8 and 9. FIG. 8 is a flow diagram illustrating the process of downloading and setting up a user's temporary computer for accessing the secure storage area, i.e. the vault. FIG. 9 is a schematic diagram of the structure of the user's temporary computer <b>4</b> once configured with the installed code.

[0050] Referring to FIG. 8, when a user uses the user's temporary computer <b>4</b> because, for example, the user's laptop computer has been lost, stolen or damaged, or because a user is away from access to the laptop <b>1</b>, a user can use any computer which has Internet access and which has a web browser to use the temporary computer <b>4</b> with the web browser to request the index page <b>25</b> in the user's directory from the web server <b>20</b> at the vault server <b>3</b>. A user need only remember the location of their user's directory which can, for example, reside at a memorable URL such as www.username.vault.com. The web server <b>20</b> returns the index page and the web browser displays the index page with the link to download the remote vault interface installer code <b>24</b> from the storage device <b>23</b> (step S<b>51</b>). A user can then select the download link in the index page (step S<b>52</b>) and the web browser downloads the remote vault interface installer code <b>24</b> to the user's temporary computer <b>4</b> (step S<b>53</b>). The remote vault interface installer application can then be opened by the user on the user's temporary computer <b>4</b> (step S<b>54</b>) and the remote vault interface application will then be installed (step S<b>55</b>). The user can then run the remote vault interface application (step S<b>56</b>). The remote vault interface application will generate the vault interface which in this embodiment is the same as the vault interface generated in the secure storage application, i.e. that illustrated in FIGS. 5 and 6 and described with reference to the flow diagram of FIG. 7. Thus a user is able to perform all of the functions that they would have been able to perform on their normal computer, i.e. their laptop computer <b>1</b>. It does however require them to enter their password in order for the application to run. Thus, in order to access the files in the secure storage area it is necessary to obtain the remote vault interface application code and to know the password in order to make it run. Since the files are encrypted in the storage area, even if someone is able to gain access to the storage area, they only gain access to encrypted files.

[0051] Once the remote vault interface application is closed (step S<b>57</b>) a window is displayed to allow a user to select to delete the remote interface application code and/or downloaded files (step S<b>58</b>). If a user selects to delete (step S<b>59</b>) the remote vault interface application code running in volatile memory deletes the code stored on the hard disk and/or any downloaded files stored on the hard disk (step S<b>60</b>). The deletion performed is a secure deletion in which the sectors of the hard disk are overwritten a number of times in order to enable reconstruction of the data. The application then finishes execution (step S<b>61</b>).

[0052] It can be seen from the description with reference to the flow diagram of FIG. 8 that the remote vault interface application includes an additional function upon termination of execution which enables the cleaning of the temporary computer. This allows a user who has downloaded the code to clean the computer to remove all traces of the application and files downloaded by the application to avoid the code or the files falling into the hands of unauthorized personnel.

[0053] In this embodiment of the present invention the vault interface provided by the remote vault interface application is the same as that provided by the secure storage application. Thus this provides a user with the same degree of functionality on a temporary computer as on their normal computer. However, the present invention is not limited to the same degree of functionality and the vault interface functionality provided by the downloaded code can be more limited. For example, it may only allow the downloading of files and not the uploading, deletion of moving of files within the vault. Thus this would merely provide a means by which files could be read from the secure storage area.

[0054]FIG. 9 is a schematic diagram of the user's temporary computer <b>4</b> after installation of the remote vault interface application code. The user's temporary computer <b>4</b> is provided with a network interface <b>40</b> which can comprise a network card, or a modem, for example. A hard disk <b>48</b> is provided to store the application code, files used by the user, and application data files used by the application. A pointing device <b>43</b> such as a mouse, a display <b>41</b> and a keyboard <b>42</b> are provided to provide a means by which a user can interface to the computer. A data memory <b>46</b> which comprises volatile memories such as RAM stores data used by the application during execution. This data includes the user password, the server address data for accessing the FTP server, the vault data generating the vault interface, and the dialler data for connecting to the ISP. A program memory <b>45</b> is provided which comprises volatile memory such as RAM for storing the application code read from the hard disk <b>48</b> for execution by a processor <b>44</b>. In this embodiment of the present invention the code comprises seven functional code modules. Six of the functional code modules are the same as for the code of the secure storage application, i.e. the interface code, dialler code, FTP code, encryption code, file manipulation code, and capacity meter code. The application code in the remote vault interface application includes a further functional module which comprises secure deletion code for performing secure deletion upon closure of the application as described hereinabove with reference to the flow diagram of FIG. 8.

[0055] The deletion function in this download code is important and can remove all traces of the application having been on the computer. Not only is it possible to delete the code and the files downloaded by the code, it is also possible for the application to delete files in the print spool if files have been printed. Thus the application can keep track of all operations performed on files downloaded by the code so that all traces of the code and operations performed by the code can be deleted from the computer.

[0056] Although the present invention has been described hereinabove with reference to a specific embodiment, it will be apparent to a skilled person in the art that modifications lie within the spirit and scope of the present invention.

[0057] For example, although the present invention has been described with reference to the inputting of a password by the user, it will be understood that this is not limited to the inputting of alphabetical characters. A password can comprise any numeric or alphabetical characters and any combination. The password can in fact comprise preferably a pass phrase which includes a longer string of characters to increase security.