WO2015135579A1

WO2015135579A1 - Key device, encryption and decryption method

Info

Publication number: WO2015135579A1
Application number: PCT/EP2014/054799
Authority: WO
Inventors: Johann Kasper Locher
Original assignee: Topas Ag
Priority date: 2014-03-12
Filing date: 2014-03-12
Publication date: 2015-09-17

Abstract

The invention relates to a method for decrypting an encrypted file (3) by means of a key device (7), wherein the encrypted file (3) can be identified via a product identification (5) and be decrypted using a decryption key (2) which can be assigned to the product identification (5) and is stored in a secure key database (6) of an encryption service provider (25). The invention further relates to a method for securely providing the decryption key, a method for encrypting a plain file using the key device, and a key device usable in said methods.

Description

Key device and encryption and decryption method

The invention relates to a keyed se as well as encryption and decryption in conjunction with the key device. In particular, the invention relates to a method for decrypting an encrypted file by means of a key device, a method for securely providing a decryption key for use in decrypting proprietary encrypted data associated with a particular user already owned by the user by means of a user-owned one A key device and a method for encrypting a clear file stored in a data processing device of a product provider by means of a key device associated with the product provider. Furthermore, the invention relates to a key device for encrypting and decrypting data. The problem of the security of personal or business data has long been the subject of many considerations and developments. With the rise of the Internet and mobile telephony, this issue has now reached the end-user sector as well, with the damage caused by the illegal use of third-party data becoming an increasingly important economic factor. On the one hand, the criminal use of personal data, such as the misuse of personal credit card information, to pay attention, on the other hand, however, the use of proprietary content by unauthorized for many businesses is a major problem.

A variety of strong encryption systems already exist, but these are hampered by the need for secure key exchange techniques. Furthermore, the implementation of an encryption system, such as for securing data in the private sector, a considerable expertise required, so that encryption systems are not used by technically poorly interested people or inadequate. Often only damage that has already occurred to the user also creates the knowledge about insufficient data security.

It is an object of the present invention to provide a comprehensive encryption and decryption system that can be quickly and easily used by an end user without relevant expertise. For providers of data products, such as software, music and movie files, the system should enable personalized encryption that ensures that the product can only be used by the authorized user. Furthermore, the system should allow the provider of the encryption solution to respond quickly to changing conditions, for example, if a particular encryption process used cracked and thus potentially unsafe. These objects are achieved by the corresponding methods and devices according to the invention.

With regard to the end user, these objects are achieved by a method according to the invention for decrypting an encrypted file by means of a key device, the encrypted file being identifiable via a product identifier and decryptable by means of a decryption key assignable to the product identifier, wherein the decryption key is stored in a secure key database of an encryption provider is. The method comprises the following steps:

- reading the product identifier associated with the file to be decrypted;

- reading out a unique user identifier of the user of the key device;

- transmitting the product identifier and unique user identifier to the cryptographic provider;

- receiving a combination key provided by the encryption provider, the combination key being generated by the encryption provider, optionally after checking the authorization of the user, by combining the decryption key with the user identifier and optionally further data;

Extracting the decryption key using the unique user identifier currently associated with the key device;

- Decrypt the encrypted file using the decryption key; and

- Outputting the decrypted file or at least parts of the contents of the decrypted file. This method, which is executed by the user's key device, provides a high degree of security since the actual decryption key is not transmitted openly. Instead, the key device contains a combination key that can be used to decrypt the file using only the user ID and a special algorithm in the key device. The respective Algorithm may be freely selected according to the skill of a skilled person in the field of encryption according to the specific requirements. The above steps are all performed by the user's key device without the user having to worry about the details of the encryption himself. The only task for the user is to associate the key device (which itself need not be personalized) with a unique user ID, in particular using the user's mobile phone number or email address as the unique user ID. The link can be made, for example, when the key device is first associated with a particular device, where the user's consent to link can be made, for example, by a security prompt on one of the connected devices. In the course of the security inquiry, it may also be necessary to enter a code or other confirmation by the user.

In order to additionally increase security, in an advantageous embodiment of the invention, position data can be read from a position determination unit of the key device and transmitted to the encryption provider. This embodiment makes it possible to specify a location where the decryption is to take place. The cryptographic provider may compare the transmitted position with predetermined data to decide if the position of the key device matches a given location. For example, an encrypted PIN code, for example for an ATM, can only be transmitted to the user when the user is at the place of installation of the ATM. This feature thus allows an extremely high level of security for a variety of applications. Advantageously, the combination key can be generated by combining at least the decryption key, the user identifier, and predetermined or user-transmitted position data, wherein the decryption key is extracted using the position data read from the position determination unit of the key device. A check of the position data by the encryption provider is thus not necessary at all, since the combination key can only be used at the location which corresponds to the position data. If the position data are not predetermined, they may have been previously transmitted in an advantageous embodiment of the key device to the encryption provider. In an advantageous embodiment of the invention, it may be provided that the position data are stored by the key device, so that after the first decryption at the specific position, the decryption can then also take place at another position. In another advantageous embodiment of the invention, the position data can be read in real time from the position determination unit of the key device and used to extract the decryption key. _" In real time" means that the position data are read out again with each decryption. Thus, the use of the combination key is only possible when the user is in a certain position.

Advantageously, the product identifier may consist of a removable memory module, a memory of a device connected to the key device, or a memory of a remote source, e.g. using a network such as the Internet. This allows a provider to encrypt one and the same product (eg a music file) with different keys, each with a serial number (or product identifier) and on different distribution channels (eg on a removable disk, a micro-device). SD card or as an internet download). The decryption key is stored in a secure database of the encryption provider, whereby an identification of the respective key via the product identifier of the respective product is possible.

Advantageously, the unique user identifier and / or optionally the position data may be read out substantially prior to each use of the user identifier. Thus, the key device is only effective when it is in the vicinity of the user device on which the unique user identifier is stored. Once the connection between the key device and the personal mobile device is disconnected, the key device no longer functions. Conversely, this means that in the key device itself no identification data must be stored, so that the key device can be sold or passed on, without a registration of the user is required. Only by linking to the mobile device does the key (ie the key device) of a particular user differ from that of another user. The expression _" essentially before each use" means that a renewed read-out of the user identifier takes place at least if it is due to the parameter is possible that the key device has been separated from the user identification carrying unit. Alternatively, the read-out of the user identification can also take place in specific intervals. In a particularly advantageous manner, the unique user identification of the user of the key device may preferably be wireless from a personal mobile device, such as a mobile phone, a portable computer, a tablet computer or an electronic entertainment device of the user, or from one into the key device or in a user's personal mobile device is inserted into an identification smart card such as a SIM card. With the exception of prepaid devices or cards, these devices or the SIM card inserted in them will only be issued after verification of the identity of the purchaser. As a result, the user identifier (for example, the telephone number assigned to a SIM card) is uniquely assigned to a single person. Use of the key device is therefore possible only for the person who also has the world's unique SIM card whose number was used in the retrieval of the decryption data (ie the combination key). Even if the combination key is stored in the key device, it is not usable for decrypting data for holders of another user ID. Preferably, the product identifier, the unique user identifier and possibly the position data can be transmitted via the network of a telephone service provider and / or via the Internet to the encryption provider. This allows a high degree of flexibility, since the respective decryption can be activated location-independently. In contrast, however, "key handover" could only be achieved by directly connecting the key device to a cryptographic provider's computer, which would further increase security for particularly security-related applications, such as online banking, as the data transmitted would no longer be secure be transmitted to a potentially interceptable network.

Another advantageous method according to the invention provides that this is the step of

Extracting the decryption key is done in a hardware-encoded processor chip with non-readable memory. A hack of encryption software working on everyone

Key device expires, is considerably more difficult and only possible with considerable technical and technical effort and expertise. Also it is not possible the to subsequently manipulate software running on an already generated chip. Should hackers be able to decrypt the hardware-encoded software of the processor chip, it can be reacted relatively quickly by using a new hardware chip in an updated version of the key device.

A further advantage according to the invention is afforded if the decrypting of the encrypted file in a hardware-encoded processor chip with non-readable memory also takes place. Thus, all security-relevant procedures are well secured against a hacker attack.

Advantageously, the decrypted file can be output as a plain file or as a file content transmitted in a stream via a wireless or wired connection to a device connected to the key device. This allows a flexible use of the encryption device with data of different types. Depending on whether the user requires the actual Klardatei (this is the case with computer programs) or if he wants to retrieve the actual media content of the file (eg the sound and / or image signal of Audio or video files), the output can be adapted to the respective situation. The output as stream (thus in particular as audio or video signal) offers the particular advantage that the files of proprietary media content (especially music recordings and video films) are not output in decrypted form, and thus can not be illegally copied without sacrificing quality.

From the point of view of the encryption provider, the invention comprises a method for the secure provision of a decryption key coded in a combination key for use for decrypting files, in particular for decrypting proprietary encrypted data already assigned to a specific user by means of a key owned by the user User key device, wherein the user is identifiable by a unique user identifier, wherein the encrypted data having a product identifier and wherein the product identifier is associated with a decryption key stored in a Schlüsseldatenbank the encryption provider, not disclosed to the user, and wherein the method by the following steps is characterized: - storing a plurality of decryption keys in the key database, the decryption keys each being assignable to a corresponding encrypted file using a product identifier obtained from a product provider;

- receiving the unique user ID of the user transmitted by the user's key device and the product ID of the file to be decrypted;

- Creating the combination key by linking at least the unique user identifier with the decryption key and optionally with position data; and

- Transfer the combination key to the key device.

In particular, the administrator of the key database is regarded as "encryption provider." The encryption provider and the manufacturer or provider of the key device should have at least intensive cooperation since the algorithms for generating the combination key always depend on the version of the key device used Therefore, in the communication between the key device and the encryption provider, at least the version number of the used key device is generally communicated so that always combination keys are generated which can be used with the respective key device The fact that the key data base can be specially secured by a variety of different measures against hacker attacks providers must be made easier. A possible (hacker) intrusion into the system of the product provider does not jeopardize the encryption security of the products already delivered by him.

Advantageously, the decryption key can be linked to a corresponding encryption key, as is the case with asymmetric encryption methods. This leaves the decryption key always in the cryptographic provider's system and is never transmitted uncoded. For a high level of security, it is therefore sufficient to protect the server system of the encryption provider in particular.

Preferably, in the method, it may be provided that, after receiving the user identifier and the product identifier, the authorization of the user is obtained by querying Authorization information is checked. As a result, it can be ensured, for example, that products distributed via download, for example, can only be decrypted after the payment of the purchase price has been confirmed and thus "released" to the user.For this purpose, a communication between the encryption provider and the product provider can be provided.

Advantageously, the position data, if they are to be used to create the combination key, be predetermined by the product provider. The product provider can thus specify at which location the user should be able to decrypt.

On the other hand, in another embodiment, the position data could also have been transmitted by the user's key device. The user can thus determine himself at which place the decryption should be possible for him. From the perspective of the encryption device of a product provider, the method for encrypting a clear file stored in a data processing device of the product provider by means of a key device assigned to the product provider is characterized by the following steps:

Receiving or retrieving the clear file to be encrypted and a product identifier associated with the file;

Generating or retrieving an encryption key associated with a decryption key;

Encrypting the clear file using the encryption key;

Transmitting the product identifier, at least one identification of the

Decryption key, and possibly a unique

Product provider ID to a key database of an encryption provider; and

Outputting the encrypted file to the data processing device of the product provider.

According to the invention, the term _" product provider" is considered to be the owner of a clear file or of a media content whose content he wishes to provide only to a specific customer or customer group, usually a buyer of the file product or of the medium. However, the term _" product provider" is not limited thereto but includes all persons or entities that want to encrypt a file using the inventive method and provide it to a third party (the user or the users). The method is performed by a key device of the product provider, wherein the key device of the product provider may be technically identical to the key device used by the users. As a result, each owner of a key device according to the invention can act both as a product provider and as a user. Thus, not only commercial offers encrypted transmitted, but it is also possible to handle private communication and data provision between two parties easily and securely encrypted. The product provider identification is advantageously transmitted to the encryption provider whenever the encryption services are commercially offered by the encryption provider and used commercially by the product provider, so that a billing assignment can take place. The services of the encryption provider can also be offered free of charge, for example to allow the buyers of the key device a secure key exchange for the private communication. In this case, the decryption key from the encryption provider only very briefly (ie until the retrieval of the combo key by the communication partner) to be stored, if this key is to be used in real time to establish communication between two users of the Keys selvorrichtung.

Advantageously, according to the invention, the encryption key can be called up by the encryption provider. This is advantageous because the computer infrastructure of a professional provider can be used to generate the random-based keys. In many cases, the methods for generating random methods in generally used computer operating systems are mathematically inadequate and thus prevent the generation of maximally secure key systems. In addition, when using an asymmetric encryption algorithm, it is possible for the decryption key to remain with the encryption provider and only be used when a user's key device _" activates" the encrypted file specifying the unique user identifier. A (hacker) intrusion into the computer system of the product provider is meaningless, since this is the decryption key at any time. In a further advantageous embodiment, the product provider can transmit position data to the encryption provider, which identify a location to which the execution of the decryption should be restricted. Symmetric encryption methods may also be used, in which case the encryption key matches the decryption key. In such a case, care must be taken that the key can not be read by unauthorized persons either during the transmission or while it is stored in a memory. The methods according to the invention interact with each other in a technical interaction and are respectively required in order to realize the underlying inventive idea, namely the provision of a secure encryption system. The combination of the methods according to the invention has the further advantage that the product provider can be sure that only the holder of the unique user ID with which the combination key is called up by the encryption provider can use the file, since the combination key only decrypts the file as long can be used as the key device is associated with the user's unique user ID. Once this association no longer exists (such as when the file was copied to an unauthorized third party), files are neither decrypted by the same device nor by any other key device. According to the selected security settings, the assignment via radio contact, such as via Bluetooth or WLAN, or by a physical connection, such as by connecting the key device to a computer via a USB interface, take place. The association becomes ineffective, for example, when the key device loses contact with the user's mobile phone (such as when it is removed from the Bluetooth wireless range) or when the key device is removed from the computer's USB port.

By a consistent use of the key device, this can be used as a personal key for a particular computer or for electronic devices in a particular network: Once and as long as the Keys selvorrichtung assigned to the system, so for example plugged into the USB port or connected via Bluetooth proprietary or personal data may be used unrestrictedly, with the data being continuously decrypted by the key device. As soon as the Key device is removed, the data are only available in encrypted form and are therefore unusable.

The invention can be advantageously used in particular for cloud computing, in that the data of a user are stored exclusively in encrypted form in the cloud system. Reading the files is only possible with a computer (or a mobile phone, smartphone, tablet, etc.) that is currently linked to the authorized user's key device. Accordingly, the invention also includes a key device for encrypting and decrypting data, wherein the device on or in a housing at least a first processor, an interface for accessing data, in particular a standardized universal interface, and / or an interface for a change Memory module, an interface for an identiflcations smart card, and a protected memory, wherein the protected memory contains a processor-executable program, which is suitable for carrying out the method steps according to the invention, which are performed by the key device. The protected memory makes it difficult to hack the encryption and decryption programs stored on the key device. An even higher level of security can be achieved according to the invention in that the protected memory and / or a key processor separate from the first processor are integrated on at least one hardware-encoded chip. By the hardware coding of the essential security-relevant algorithms to be executed by the key device, a software manipulation which has the goal of cracking the encryption system is rendered impossible. Moreover, a considerable effort is required to find out from the chip which algorithms are used by the program according to the key. Nevertheless, should the programming of a current system be cracked, in the next production series of the key device, the algorithms can be changed by relatively simple adjustments (such as the parameters or the algorithms used themselves).

Advantageously, the key device may further comprise a data transmission unit and / or a second standardized universal interface. The data transmission unit or the second interface allow the construction of a (radio) Network or communication over an existing wireless network, such as via Wi-Fi, Bluetooth or a mobile phone network and communication with several different devices. The key device can thereby group several communication devices of the user in a common network and organize all the encryption and decryption required and desired in that network. The decryption may involve personally acquired proprietary files, such as software, music or video files, on the other hand, the private or business correspondence and communication of the user can be encrypted or decrypted.

All personal devices in the network can therefore only be used if the key device is present. A theft of one of the devices makes at least the data stored on it useless for the thief. However, should a thief also come into possession of the key device, it would be easy to reach and block the key device via their own means of communication, if the honest owner desires this security feature. Also, a location of a stolen key device would be easily possible, as long as the unlawful owner uses the also stolen identification chip card. In a further advantageous embodiment of the invention, the second standardized universal interface can be designed as a counterpart to the first standardized universal interface. Thus, the encryption device can be used in a so-called "Dasy Chain", in which several devices provided with the same USB interface are connected in succession to the same USB interface and communicate with one another in the form of a bus system Key device (s) associated with a different user ID, USB storage devices, radio modules, or the like.

Advantageously, the interface for the identification smart card can enable the insertion of a mobile phone SIM card. The phone number assigned to the SIM card can then be used by the key device as a unique user identifier without the user's mobile phone having to be connected to the key device. Furthermore, in a preferred embodiment, the key device may comprise a position determination unit, such as a GPS chip. This makes it possible to realize localized encryption methods in which, when the combination key is called up, the respective GPS position is also transmitted to the encryption provider and taken into account by the latter in the formation of the combination key. Decryption of data is only possible when the key device is at a certain position.

This feature can be used, for example, for cash dispensers because it can be easily checked whether the authorized holder of a credit card (or its key device and mobile phone) is actually at the cash dispenser. For this example, a code can be encrypted sent to the user's mobile phone, which is displayed correctly only if the user is in front of the cash dispenser or at a certain payment terminal. This code then replaces the known PIN code. However, since the code is used only once, it is not necessary to hide the PIN entry from any prying eyes by covering the numeric keypad. Misuse is only possible if a thief steals both the credit card and the key device and the device containing the unique user identifier (e.g., the mobile phone) at the same time. Once the theft is detected, the risk of being caught is very great for the thief, as he must always be able to be located via the key device or mobile phone. Moreover, simple deactivation functionalities can be integrated into the key device, with which the system can be blocked at any time in the event of theft. The risk of unauthorized withdrawal at ATMs can be further reduced by a conventional PIN code is extended by a variable, encrypted transmitted part. The user would then have to enter both the known PIN and the securely transmitted PIN at the terminal to identify themselves.

The invention will be described by way of example with reference to preferred embodiments with reference to the accompanying drawings, in which:

Fig. 1 shows schematically based on a preferred embodiment of the invention, the essential elements involved in the inventive and Entschlüs determination process and method steps schematically and Fig. 2 shows a preferred embodiment of the key device according to the invention and its essential components schematically.

In the accompanying drawings, like elements are identified by like reference numerals.

1 shows a schematic overview of the parties involved in the method according to the invention, in particular a product provider 26, an encryption provider 25 and a user 9, wherein the respective areas which can be assigned to a specific party are enclosed by a broken line.

In the upper left corner of FIG. 1, the area of the product provider 26 is shown. The product provider 26 is assigned a unique product provider identifier 8, which is used in particular in the course of communication with the encryption provider 25 in order to identify the product provider 26.

The product provider 26 is the owner of at least one media content 1, which he wants to make available to a specific user 9 (or even multiple users) in encrypted form. In the context of this invention, the term media content refers to information in the broadest sense that can be converted into digital data and stored as such. In particular, as media contents, for example, images, films, tarpaulins, sound signals, documents, books, program instructions (e.g., computer or control programs) or combinations thereof are considered, regardless of their physical nature. In particular, any material that is amenable to copyright protection, as well as its digitally representable images may be referred to as media content.

The digital image of media content 1 stored in a file is referred to herein as plain file 4. As a clear file 4 computer files are designated in particular, from which about using a computer program, the original media content 1 can be made usable for a user, either by displaying an image, document, plan or book text, either by playing an audio and / or video signal , or by performing an appropriate program or otherwise. To prevent the use of the clear file 4 by unauthorized persons, this can be converted into an encrypted file 3. An encrypted file is any file that is encrypted by any encryption method, regardless of the level of security and the type of encryption used.

In order to convert the clear file 4 into an encrypted file 3, the encryption method uses a specific encryption key 2 'to which one or more decryption keys 2 are assigned. Thus, each clear file 4 which has been converted into an encrypted file 3 with a specific encryption key 2 'by means of a specific encryption method can be converted back to the plain file 4 with a decryption key 2 corresponding to the encryption key 2' and a decryption method matching the encryption method. Encryption methods which can be used are all methods known in the art, and the invention can be used with both symmetric and asymmetric encryption methods. In asymmetric methods, the encryption key 2 'corresponds to the public key and the decryption key 2 corresponds to the private key. In the case of symmetrical methods, both keys 2, 2 'are identical. The encryption methods are performed by a key device 7 'associated with the product provider 26, the encryption procedures being described in detail below.

In the illustrated case, the encryption key 2 'is provided by the encryption provider, whereby the encryption key 2 is not transmitted to the system of the product provider. The product provider 26 also does not have to worry about selecting a particular encryption method since the encryption is performed by the key device 7 'available as a finished product. The communication with the encryption provider 25 for obtaining the encryption key 2 'is preferably carried out independently by the key device 7'. Each encrypted file 3 is assigned a unique identifier, from which the encryption key 2 'used for the encryption can be uniquely identified. This unique identifier is referred to below as product identifier 5 and it may either be awarded by the product provider 26 on the basis of previously defined criteria, or it wild when encrypting the Klardatei 4 generated by the key device 7 'based on previously defined criteria and the product provider 26 announced together with the encrypted file 3. In this case, the product identifier 5 can also be stored in a part of the encrypted file 3, for example in an unencrypted header section. Alternatively, the product identifier can be stored separately from the encrypted file 3, wherein the association is stored in a corresponding database of the product provider. The product identifier 5 is transmitted in the course of the encryption process by the key device 7 'in such a manner to the encryption provider 25 that the latter is stored in the It is able to use the product identifier 5 to identify the decryption key 2 that is usable for decrypting the encrypted file 3 identified with the product identifier 5. Preferably, the product provider identifier 8 is also transmitted to the encryption provider 25, for example, to allow offsetting. In the following, the term "product" generally refers to the sum of the objects (eg storage media, packaging, instructions etc.) and information (eg encrypted and unencrypted files) which are transmitted by the product provider 25 to the user 9 for its use also consist of several files, of which only a part is encrypted, but which is essential for the use of the product.It is also irrelevant whether the product is transmitted for payment or free of charge to the user 9. The invention can also be used for the encrypted transmission of For example, the system according to the invention may also be used to establish secure communication between two or more parties, with the parties alternately representing the roles as _"one-to-one" between a product provider 25 and a user 9. Product provider "and take it as a _" user " n. The data packets of the encrypted communication would then essentially correspond to the "product".

If the encryption key 2 'of the key device 7' is provided by the encryption provider 25, the product identifier 5 can also be transmitted to the encryption provider 25 in the course of the communication between the key device 7 'and the encryption provider 25, so that for this the corresponding assignment of the product identifier 5 to the decryption concludes 2 is possible. If the key device 7 ', however, on a previously transmitted sentence different Encryption key 2 'has (for example, for offline operation), then in addition to the product identifier 5 also an identification of the key set used and the key used from it would be transmitted to the encryption provider. Alternatively, the key device 7 'may itself generate the encryption key 2' and the corresponding decryption key 2, and then transmit the decryption key 2 together with the product identifier 5 to the encryption provider 25. The communication between the key device 7 'and the encryption provider 25 may optionally also be encrypted, for example by means of conventional encryption methods.

Typically, the files are stored and managed within the product provider 26 within a computer system or a network of the product provider 26, the invention being usable regardless of the type of storage solutions and respective computer and network systems. In the illustrated embodiment, the product provider 26 sells Product to one or more customers (these are the users 9), wherein the product may be a storage medium, such as the removable storage module IS, on which the encrypted file 3 is stored. The removable memory module 15 is provided with the product identifier 5, which makes it possible to uniquely identify the media content and the method used for encryption as well as the encryption key 2 'used. On the basis of the product identifier 5 alone, however, it is in no way possible to decrypt the encrypted file 3. As stated above, the product identifier 5 can be stored in a non-encrypted part of the encrypted file 3, it can be contained in a separate file, which is stored together with the encrypted file 3 on the removable memory module 15, it can on the memory module It may be printed on the packaging or in an accompanying booklet enclosed with the product, or it may be contained in a contactless readable medium, eg an RFID chip be. Any storage module may be used as the removable storage module 15, with standardized standard products, such as a CD or DVD, a USB memory or a memory card (eg a flash card or memory card) being preferred. In Fig. 1 as a removable storage medium 15 a MicroSD card is exemplified. The removable memory module 15 can be used as a product in any way, for example in the individual, large or Mail order, to the end user. As one skilled in the art will appreciate, the distribution of a removable memory module IS is only one of many ways to communicate a file to a user 9. In particular, the file may also be distributed over a network, such as the Internet, or it may be stored in and distributed with the hardware used to retrieve the media content. The invention is not limited to the use of certain electronic devices.

The user 9, who has honestly acquired the product stored on the removable storage medium IS, can use it only after he has "activated" it by means of his own key device 7, the key device 7 of the user 9 being used inter alia with the As will be described in more detail below, the key device 7 is able to communicate with different devices and networks in different ways, on the one hand with one or more devices owned by the user 9, and on the other hand can communicate with remote systems and databases, in particular with the cryptographic provider 25 system.

Among the devices of the user 9 with which the key device can communicate include, in particular, mobile phones 27, portable or stationary computers 28, tablet computers or e-readers 29, or electronic entertainment devices 30, such as a portable music player or video player , The list of devices is only illustrative and not restrictive. All user electronic devices capable of communicating with the key device and storing and / or using the files and / or media content may be advantageously used in conjunction with the invention.

In order to be able to use the key device 7 according to the invention, the user 9 must be uniquely identifiable, for example via a unique user ID 10. For example, each (mobile) telephone number offers an advantageous possibility of unambiguous identification since it is assigned only once worldwide. However, other unique user identifiers may be used, such as an email address or any other identifier that allows unique identification. It is not so crucial that the owner of the unique user ID 10 also personally in Experience (this is not always the case, for example, with prepaid mobile phone numbers) but that the identifier is unique throughout the network (in the case of the Internet or the telephone network worldwide). As will be described below, the user 9 links that from acquired product with a particular unique user ID 10, the product subsequently being used only by the owner of that user ID. The unique user identifier 10 may be stored on an identification chip card 17, the security being higher when this identification chip card 17 is issued by a trustworthy institution, such as SIM cards that use in mobile phone networks as identification smart cards 17 that is the case.

Since in a mobile telephone network the owner of a particular mobile phone number (and only this) is always in possession of the corresponding SIM card, in a particularly preferred embodiment of the invention, the unique user identifier 10 is a mobile phone number of the user 9.

Due to the communication capabilities of the key device 7 set forth in detail below, it is capable of communicating with all of the user's devices, or accessing the respective storage devices required for use of the media contained in the encrypted file 3 in an unrestricted or restricted manner , Thus, the key device 7 manages a network associated with the user 9, which uses the key device 7, in particular, to either convert encrypted files 3 into plain files 4, or to pass them on to a device suitable for the use of the clear file 4, or encrypted Convert files 3 into a file content 24 (for example, a music or movie signal) that can be played back or output via one of the user's devices without the plain file 4 itself being transmitted to this device. However, the key device must first have the decryption key 2, which is initially stored securely in a key database 6 of the encryption provider 25. For this purpose, the product acquired by the user 9 (ie essentially the encrypted file 3 provided with a product identifier 5) is linked to the unique user ID 10 of the user. This link can be via a simple Query or a menu-driven command can be triggered, wherein the query or the menu can be displayed on one of the devices of the user 9, which communicates with the key device. Alternatively, the key device 7 could also include a user interface, such as a display and a keypad, through which control of the link is possible. Once the key device receives notification from the particular device that the user 9 has instructed to associate the particular product with the particular user ID 10, it reads that user ID from the identification smart card 17 (which is only in the physical presence of that smart card 17 is possible) and transmits the user identifier 7 together with the product identifier 5 to the encryption provider 25. The communication between the key device 7 and the encryption provider 25 can either via a secure or unsecured connection via the Internet, the communication network of the telephone provider, a separate network of Encryption provider or a combination thereof. For particularly security related applications, such as in banking or in the eGovernment area, it may also be desired and required that the key device for activating the encrypted file 3 be directly connected to the network of the cryptographic provider 25 or physically located in a particular location located in the area of a bank counter or public office. In this case, the position of the key device can also be determined by means of a positioning system, such as a GPS sensor connected to the key device.

The encryption provider 25 is now able to use the received product identifier 5 to read the decryption key 2 required for decrypting the particular encrypted file 3 from its key database 6. If appropriate, the encryption provider 25 can first check on the basis of the unique user identifier 10 whether the owner of this user identifier 10 is authorized to use the product, for example by directing a request to the product provider 26. This security feature is particularly useful for online products: Before downloading the product purchased online (ie, the encrypted file 3), the user 9 could tell the product provider 26 what unique user ID 10 he wants to associate with the product. During the _" activation" of the product, the encryption provider 25 can now direct a request to the product provider 26 as to whether the user identifier 10 transmitted to him for activation of the product has exceeded the user identifier specified during the purchase. This will prevent a third party (such as an "eavesdropper", which is about to disappear in the course of the Downloads has unauthorizedly in possession of a copy of the encrypted file 3 and the product identifier 5 has arrived), has the opportunity to unlock the product instead of the honest owner with its own user ID, before the honest owner has done. After the encryption provider 25 has checked the authorization in accordance with the specifications, the corresponding decryption key 2 is retrieved from the key database 6 and possibly also deleted, provided that the key was intended for single use only. For security reasons, however, the encryption provider 25 does not transmit the decryption key 2 itself to the key device of the user 9, but a combination key 11 which is generated by means of a specific algorithm. The algorithm combines the decryption key 2 with the unique user identifier 10 in a reversible manner. Without knowing the algorithm used, it is not possible for an attacker to read out the decryption key 2 from the combination key 11, even if the attacker knows the unique user identifier 10. The user's key device 7 is capable of extracting the decryption key 2 from the combination key 11, and the application performing this step in the key device 7 may be particularly secured against read-out, such as by the application being hardware-coded. The key device 7 stores the combination key 11 and, if necessary, can extract and use the decryption key 2 therefrom.

The algorithm used by the encryption provider 25 to produce the combination key 11 and the corresponding algorithm used by the key device to extract the decryption key 2 are of particular importance to the subject invention. The highest level of security can be achieved as long as the algorithm used is kept secret. Should the algorithm have become known or cracked, the transmission of the combination key 11 would no longer be secure and an attacker who has taken possession of the combination key 11 and knows the corresponding unique user identifier could thus generate the decryption key 2. The system would still offer a considerable degree of security, since an attacker not only requires the decryption key 2, but also the encrypted file 3, which can only be obtained from two separate listening or hacking processes, targeted attacks however, could be successful, which is neither desired by the providers nor by the users of the encryption system.

In essence, the algorithm can be considered as a symmetric encryption method in which the decryption key 2 is encrypted using the unique user identifier 10 (as a key). As experience has shown, however, it can not be assumed that a specific algorithm can be kept secret in the long run. Rather, it can be expected that a higher complexity of the chosen algorithm only increases the duration required to crack the respective code, but in the end can not prevent this. However, to further enhance security, the creation of the combination key 11 could also be accomplished using an asymmetric encryption technique, where the key device 7 provides the public key to the cryptographic provider. In this case, even after the knowledge of the algorithm used would be given a very high security.

In connection with the algorithm for generating the combination key 11, the advantages of the invention are revealed in two ways: Firstly, the algorithm required for extracting the decryption key 2 runs only on the encryption key, and can there be particular by some features of the key device according to the invention be well protected. As will be explained in more detail in the context of the detailed description of the key device, the application executing the algorithm may be hardware encoded on a chip of the key device, so that the program flow is only through very expensive techniques, such as the chip reverse engineering, in experience can be brought. This requires a targeted effort by the attacker and takes time.

If the algorithm for creating the combination key 11 was finally broken, the hardware layout of the key hardware can be changed with a manageable effort and relatively quickly and put on the market in a new version. Either the entire algorithm or only a few important parameters can be changed. The efforts of third parties to crack the algorithm would essentially be reset to the starting point. For applications with lower security requirements, the old version of the key hardware can still be used. For this reason, by the key device 7 in the Communication with the encryption provider 25 preferably also transmits the version number, so that the encryption provider 25 for generating the combination key each uses the appropriate algorithm. To generate the combination key, the encryption provider can also use a key device in which the application is hardware-coded to carry out the algorithm. Preferably, the key device 7 of the user and / or the key device 7 'of the product provider of a particular version may each be identical. Optionally, the key device (not shown) of the encryption provider may be identical, but the problems that may arise for the security of the overall system must be taken into account.

The algorithm used may be arbitrarily selected according to one of ordinary skill in the art of cryptography, which algorithm must meet the following criteria: The algorithm combines the decryption key 2 and the unique user identifier 10 into a combination key 11. There is a corresponding algorithm, with from the combination key 11 using the unique user identifier 10 of the decryption key 2 can be extracted again. As an independent provider, the encryption provider 25 can make its services available to different product providers 26 and users 9 for a fee or free of charge. For example, encryption provider 25 could simultaneously be the manufacturer or provider of the key device, but this is not mandatory. In particular, the same encryption system could be used by a variety of different encryption providers, each providing their services to their own product providers and users. This is indicated in Fig. 1 by the two additionally shown product providers 25 'and 25 "each managing their own key database 6, 6. The different encryption providers 25, 25', 25" may be interconnected and exchange information as they may but also act independently and separately from each other. It is also possible for the encryption provider 25 to be an abstract unit, for example a separate system area of a group-wide IT system, which manages the encryption used in the group using the methods according to the invention. The encryption provider 25 could also be a delimited area of a computer system or software program. At least parts of the process steps that occur at the product provider 26, the encryption provider 25 and / or the user 9 could be performed by the same computer system or software program. Such an embodiment could be useful, for example, if the inventive method for encrypting a user's own data is used, in which case the user 9 and the product provider 26 are identical units. The units shown in FIG. 1 (encryption provider 25, product provider 26 and user 9) are therefore not necessarily spatially or systematically delimited areas, rather this illustration serves to explain the method according to the invention, which can be implemented in different ways in different hardware systems. and software environments can be used.

The communication between the participating units can be done in all possible ways that are known in the field. In some applications, one can increase the security of the system by disabling individual communication steps from automated electronic processing. For example, it may be required that the product identifier 5 and the unique user identifier 10 be communicated to the cryptographic provider 25 in different ways. The user ID 10 could be transmitted, for example, by voice over the telephone and evaluated via a voice recognition system. In other cases, the user identifier 10 (and / or the product identifier 5) could be entered into a keypad at a terminal of the cryptographic provider. While this would increase security, at the same time, usability would be compromised.

The key device 7, 7 'used by the user 9, by the product provider 26 and optionally by the encryption provider 25 and their essential components will now be explained in more detail with reference to FIG. Fig. 2 shows the key device 7, 7 'in a schematic representation, wherein the individual components are housed in a housing 12 having a first universal interface 13, with which the device can be connected to any computer system, which also has a similar universal interface features. The interface is advantageously a standardized bus interface, such as a USB interface. On the housing, a second universal interface 21 is further provided via which further electronic devices can be connected. Such a juxtaposition of several electronic devices on similar bus interfaces in the form of a so-called _" Dasy chain" are well known in the art and must not be described in detail.

As further physical interfaces, the key device 7, 7 'has an interface 14 for an exchange memory module and an interface 16 for an identification chip card. Advantageously, the removable storage module used is a small-sized storage module, such as a microSD card. The identification smart card may be a conventional SIM card or a card having similar functionality.

As further interfaces, the key device 7, 7 'has a GPS sensor 31 and one or more data transmission units 20, such as a WLAN and / or a Bluetooth chip. Furthermore, the key device 7, 7 'on a protected memory 19, a random access memory 22, a processor 18 and a key processor 23, on. These components are connected to one another in a conventional manner known to the person skilled in the art, wherein the processor 18 can execute programs which are stored in the working memory 22, for example. As one of ordinary skill in the art will appreciate, individual components such as protected memory 19 and key processor 23 may be integrated on a single chip.

The protected memory 19 may, for example, be a chip on which the programs and algorithms essential for encryption are stored in hardware-encoded form. Although these programs and algorithms could also be executed directly by the processor 18 in an alternative embodiment, a separate key processor 23 is preferably provided for this purpose, which is particularly protected against hacker attack, since it handles only the programs required for the encryption. This can prevent malicious programs, which have been introduced into the main memory 22, from damaging the method steps that are essential for encryption. Preferably, the key device 7, 7 'has its own energy source, such as a battery 32, so that it can also be used without connection to a power supply. The detailed development and creation of a circuit layout for the key device, as well as the development or selection of corresponding hardware chips, are well within the ordinary skill of a person of ordinary skill in the art having knowledge of the teachings set forth herein. For reasons of clarity, the connections between the individual components are therefore not shown in FIG.

Dimensions of the housing 12 are preferably sized so small that just about all components can be accommodated. This allows the key device 7, 7 'be so small that it can be easily inserted into a trouser pocket or used as a keychain.

With reference again to FIG. 1, the individual method steps of a preferred embodiment of the method according to the invention will be explained in detail in the following. In step II-a), the clear file 4 to be encrypted and a product identifier 5 associated with the file are transmitted in the system of the product provider 26 to the key device 7 'of the product provider 26.

At step ΙII-b), the key device 7 'retrieves from the encryption provider 25 an encryption key 2' associated with a decryption key 2. For asymmetric encryption methods, in which the decrypting key 2 differs from the encryption key 2 ', the decryption key 2 itself is not transmitted and remains in the database of the encryption provider. Alternatively, the encryption key 2 'can also be created by the key device, in which case, in addition to the illustrated method steps, the decryption key 2 should also be transmitted to the encryption provider. In order to enable "off-line operation" of the key device 7 ', the encryption key 2' (possibly together with several others Encryption keys) have been passed in advance to the Schlüsselvoirichtung.

In step II-c), the key vaulting device encrypts the clear file 4 using the encryption key 2 ', generates an encrypted file 3 and, in step II-e), transmits the encrypted file 3 to the data processing device of the product provider 26, which then sends the file for transmission prepared the user 9, for example by storing on a disk (such as the removable memory module 15), which is marked with the product identifier 5.

Furthermore, the key device 7 'in step ΙII-d) transmits the following information to the encryption provider 25:

the product identifier 5,

- the product provider ID 8, and

Information from which the encryption provider 25 can uniquely identify the decryption key 2 to be used for decrypting the encrypted file 3.

In step ΙI-a), the encryption provider 25 stores the data received from the product provider 26 in a key database 6 in which a plurality of further decryption keys 2 can also be stored by the same and, if appropriate, by other product providers. Each decryption key 2 can be assigned by the encryption provider by means of the key database 6 and by means of the product identifier S stored therein received by the product provider 26, to a corresponding encrypted file 3.

For decrypting the encrypted file 3, the product identifier 5, which is assigned to the file 3 to be decrypted, is first read out in step 1a) from the key voyage 7 of the user who has legitimately acquired the encrypted file 3 from the product provider. Alternatively, the product identifier 5 may also be read by the user 9, for example, from a packaging imprint and entered manually into a user interface connected to the key device 7. In step Ib) reads the Schlüsselvolrichtung 7 the unique user ID 10 of the user 9 of the key selvorrichtung 7, wherein this is preferably done by reading an identification chip card 17 (eg a SIM card), which is either inserted into a corresponding interface of the key device 7 is, or which is in an electronic device, such as the user's mobile phone 27, wherein the key device 7 for reading the user ID 10 communicates with the mobile phone either via a wireless connection (eg Bluetooth or WLAN) or via a connected interface.

At step I-c), the unique user identifier 10 of the user 9 and the product identifier 5 of the file 3 to be decrypted are transmitted from the key device 7 to the encryption provider 25 and received by the encryption provider 25 at step Π-b.

After the encryption provider 25 has possibly checked the authorization of the user 9 for using the encrypted file 3 (for example by asking the product provider 26), the encryption provider 25 creates a combination key 11 at step Π-c) by using a defined algorithm to generate the unique user identifier 10 and the decryption key 2 combined, where appropriate, also other data can be included in the algorithm.

Then, in step Π-d), the encryption provider transmits the combination key 11 to the key device 7 of the user 9, who receives it in step I-d) and then stores it for use. In order to make the encrypted file 3 usable for the user 9, the key device 7 of the user 9 uses the unique user ID 10, which it may read anew in each decryption process (step Ib), and extracts it in step Ie) by means of a trusted algorithm the stored combination key 11 the corresponding decryption key (2).

Then, in step If), the encrypted file 3 is decrypted using the extracted decryption key 2. In step Ig), the decrypted file or at least parts of the contents of the decrypted file are then output to an electronic device connected to the key device 7. The communication with the respective electronic device, for example, either directly via one of the universal cutting parts 13, 21, via a wireless communication, or by storing on a removable memory module 15 done.

All procedural steps in which the decryption key 2 is used by the key device 7 are preferably handled by the key processor 23, wherein the decryption key 2 is used each time from the combination key 11 (stored in the main memory 22) and the currently read unique user identifier in the key processor 23 is newly generated. As a result, the decryption key 2 itself is never stored in a memory and therefore can not be read by espionage programs. If only parts of the decrypted file are output to a connected device, for example in the form of an audio or video signal, it can be provided that the key device 7 reads out the unique user identifier 10 from the identification chip card 17 at regular intervals. Now, if the identification chip card 17 is removed, or if the contact to the electronic device in which the identification chip card 17 is located, breaks off, then the output of the decrypted signal ends. Thus, the "encrypted" file 3 "released" for a particular user identifier 10 can only be used if the device with the identification chip card 17, for example the mobile telephone of the user, is located in the communication area of the key device.

LIST OF REFERENCE NUMBERS

Media content 1

Decryption key 2

Encryption Key 2 'Public Key

Encrypted file 3

Clear file 4

Product ID 5

Key database 6

Key device 7, 7 '

Product Provider ID 8

User 9

Unique user ID 10 e.g. mobile number

Combination key 11

Housing 12

first universal interface 13

Interface 14 for a removable memory module IS

Interface 16 for an identification chip card 17

Processor 18

protected memory 19

Data transmission unit 20

second universal interface 21

Main memory 22

Key processor 23

File content 24 e.g. a music or movie signal encryption provider 25

Product Provider 26

Mobile phone 27

Computer 28

Tablet computer 29

electronic entertainment device 30

GPS sensor 31

Battery 32

Claims

Expectations

1. Method (I) for decrypting an encrypted file (3) using a key device (7), wherein the encrypted file (3) can be identified via a product identifier (5) and decrypted using a decryption key (2) that can be assigned to the product identifier (5). , wherein the decryption key (2) is stored in a secure key database (6) of an encryption provider (25), and wherein the method is characterized by the following steps:

I-a) reading out the product identifier (5) that is assigned to the file to be decrypted; I-b) Reading out a unique user ID (10) of the user (9).

key device (7);

I-c) transmitting the product identifier (5) and the unique user identifier (10) to the encryption provider (25);

I-d) receiving one provided by the encryption provider (25).

Combination key (11), whereby the combination key (11) comes from the encryption provider

(25), if necessary after checking the authorization of the user (9).

Combining the decryption key (2) with the user ID (10) and possibly further data was generated;

I-e) Extracting the decryption key (2) using the unique

User ID (10) that is currently assigned to the key device (7);

I-f) Decrypt the encrypted file (3) using the decryption key

(2); and

I-g) Outputting the decrypted file or at least parts of the contents of the decrypted file.

2. The method according to claim 1, characterized in that position data is read from a position determination unit (31) of the key device (7) and transmitted to the encryption provider 25 in step I-c).

3. Method according to one of claims 1 or 2, characterized in that the combination key (11) is generated by combining at least the decryption key (2), the user identification (10), and predetermined position data or position data transmitted by the user, the extraction of the Decryption key (2) in step Ie). The position data read out from the position determination unit (31) of the key device (7) is used.

4. The method according to claim 3, characterized in that in step I-e) position data in real time from a position determination unit (31) of the key device

(7) can be read out and used in step I-e to extract the decryption key (2).

5. The method according to one of claims 1 to 4, characterized in that the product identifier in step I-a from a removable memory module (15), a memory of a device connected to the key device (7) or from the memory of a remote source, e.g using a network such as the Internet.

6. Method according to one of claims 1 to 5, characterized in that the unique user identification (10) and/or, if applicable, the position data in

Essentially read out before each use of the user ID (10).

7. The method according to any one of claims 1 to 6, characterized in that the unique user ID (10) of the user (9) of the key device (7) is preferably wireless from a personal mobile device, such as a mobile phone (27), a portable computer (28), a tablet computer (29) or an electronic entertainment device (30) of the user (9), and/or an identification chip card (17) inserted into the key device (7) or into a personal mobile device of the user , such as a SIM card, is read.

8. The method according to any one of claims 1 to 7, characterized in that the product identifier (5), the unique user identifier (10) and optionally the position data in step I-c are sent to the encryption provider (25) via the network of a telephone service provider and/or via the Internet ) are transmitted.

9. The method according to one of claims 1 to 8, characterized in that the extraction of the decryption key (2) in step Ie takes place in a hardware-coded processor chip with non-readable memory.

10. The method according to one of claims 1 to 9, characterized in that the decryption of the encrypted file (3) in step I-f takes place in a hardware-coded processor chip with non-readable memory.

11. The method according to one of claims 1 to 10, characterized in that the decrypted file in step I-g as a clear file or as a file content (24) transmitted, for example, in a stream via a wireless or wired connection to a key device (7) connected device is output.

12. Method (ΙI) for securely providing a decryption key (2) encoded in a combination key (11) for use in decrypting files in a method according to one of claims 1 to 11, in particular for decrypting proprietary files for a specific user (9) assigned encrypted data (3) already in the possession of the user (9) by means of a key device (7) in the possession of the user (9), the user (9) being identifiable by a unique user ID (10), the encrypted Data (3) have a product identifier (5) and wherein the product identifier (5) is assigned a decryption key (2) stored in a key database (6) of an encryption provider (25) that is not disclosed to the user (9), and wherein the method is carried out by the following steps are marked:

ΙI-a) storing a plurality of decryption keys (2) in the key database (6), wherein the decryption keys (2) can each be assigned to a corresponding encrypted file (3) using a product identifier (5) received from a product provider (26);

ΙI-b) receiving the unique user identifier (10) of the user (9) transmitted by the key device (7) of the user (9) and the product identifier (5) of the file (3) to be decrypted;

ΙI-c) creating the combination key (11) by linking at least the unique user ID (10) with the decryption key (2) and, if necessary, with position data; and

ΙI-d) Transmitting the combination key (11) to the key device (7).

13. The method according to claim 12, characterized in that the decryption key (2) is linked to an encryption key (2 ').

14. The method according to claim 12 or 13, characterized in that after receiving the user identification (10) and the product identification (5) (step ΙI-b), the authorization of the user (9) is checked by querying authorization information.

15. The method according to one of claims 12 to 14, characterized in that position data is specified by the product provider (26).

16. The method according to any one of claims 12 to 14, characterized in that position data was transmitted from the user's key device.

17. Method (DU) for encrypting a clear file (4) stored in a data processing device of a product provider (26) by means of a key device (7 ') assigned to the product provider (26), the generated encrypted file (3) being encrypted by means of a method according to one of Claims 1 to 11 can be decrypted, and wherein the method is characterized by the following steps:

ΙII-a) receiving or retrieving the clear file (4) to be encrypted and a product identifier (5) assigned to the file;

ΙII-b) generating or retrieving an encryption key (2') associated with a decryption key (2);

ΙII-c) encrypting the clear file (4) using the encryption key (2');

ΙII-d) transmitting the product identifier (5), at least one identification of the decryption key (2), and optionally a unique product provider identifier (8) to a key database (6) of an encryption provider (25); and

ΙII-e) Outputting the encrypted file (3) to the product provider's data processing device (26).

18. The method according to claim 17, characterized in that the encryption key (2 ') is retrieved from the encryption provider.

19. The method according to claim 17 or 18, characterized in that the product provider (26) transmits position data to the encryption provider (25), which indicate a location to which the implementation of the decryption should be limited.

20. Key device (7, 7') for encrypting and decrypting data, characterized in that the device has at least one first processor (18), an interface for accessing data, in particular on and/or in a housing (12). a standardized universal interface (13), and / or an interface (14) for a removable memory module (15), an interface (16) for an identification chip card (17), and a protected memory (19), the protected Memory (19) contains a program executable by a processor (18, 23) which is suitable for carrying out steps I-a to I-g in claim 1 and / or steps ΙΠ-a to ΙΠ-e in claim 17

21. Key device (7, 7') according to claim 20, characterized in that the protected memory (19) and a key processor (23) separate from the first processor (18) are each or jointly integrated on a hardware-coded chip.

22. Key device (7, 7 ') according to claim 20 or 21, characterized in that the key device (7, 7') further has a data transmission unit (20) and / or a second standardized universal interface (21).

23. Key device (7, 7') according to one of claims 20 to 22, characterized in that the second standardized universal interface (21) is designed as a counterpart to the first standardized universal interface (13).

24. Key device (7, 7 ') according to one of claims 20 to 23, characterized in that the interface (16) for an identification chip card (17) enables the insertion of a mobile phone SIM card.

25. Key device (7, 7 ') according to one of claims 20 to 24, characterized in that the key device has a position determination unit, such as a GPS sensor (31).