EP1828964A1

EP1828964A1 - Crypto wireless tag

Info

Publication number: EP1828964A1
Application number: EP05818135A
Authority: EP
Inventors: Jörg Eberwein; Stefan Werden; Bernhard Roeger
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-12-09
Filing date: 2005-12-07
Publication date: 2007-09-05
Also published as: US20060133606A1; DE102004059391C5; US7881469B2; DE102004059391A1; DE102004059391B4; WO2006061005A1

Abstract

The crypto wireless tag contains a data record characterized in that it comprises at least one crypto data block.

Description

description

Crypto Wireiess tag

The invention relates to a wireless tag ('wireless tag', often also 'RFID (Radio Frequency Identification) tag', or 'wireless label' called) with cryptographic property (hereinafter 'crypto wireless tag' called), ie one Property to hold blocks of data that contain encrypted data, cryptographic keys, and / or digital signatures, a method to operate the crypto-wireless tag, and a wireless cryptosystem to use the crypto-wireless tag.

Wireless ^' tags are tags, such as

Labels containing a record of different lengths - usually in powers of 2, d. H. 32 bit, 64 bit, 128 bit etc. - carry. The data records can be read out and / or written without contact, typically via a radio signal (RFID tag) issued by a reading device and / or a writing instrument. The type of readout is defined via a read protocol which is specified via a command set. Reading out or writing can be done by standards, as for example by the organizations

EPC-global (eg EPC Tag Data Standards Version 1.1, Rev. 1.25);

EAN.UCC (eg General EAN.ÜCC Specification Version 5.0); ISO, IEC, Committee JTC-I of ISO and IEC included

Automatic Identification and Data Capture (AIDC), specifically Subcommittee 31 (SC31) with Workgroups 1-3 (WGl-3) on 'Automatic Identification and Data Capture' and WG4 on ¹ RFID for Item Management '; ANSI, z. B. ANSI INCITS Tβ - RFID and ANSI INCITS T20 - Real Time Location Systems (RTLS) have been passed or have been adopted. The data records may contain one or more data blocks, such as a data block for a checksum, a data block for a manufacturer identification etc. In principle, one or more freely available data blocks may also be present in the data record, eg. B. for manufacturer-specific product information.

In the previously known wireless tags, it is problematic that the record is usually read by unauthorized persons. It was proposed - see "Der Spiegel" 46/2004, p. 194, columns 1 and 2 - to protect the RFID tags with passwords, which is expensive, slow and expensive.

Another problem is that the one read

Record can be interpreted and modified with relatively little effort. As a result, product pirates - possibly knowing the records of authentic wireless tags - could create their own tags, which do not allow a distinction to the original product during normal operation. Also, manufacturers or distributors could change a commodity information, e.g. As an expiration date, etc., without this being easy to prove.

It is therefore the object of the present invention to provide a comparatively simple and fast way of solving one or more of the above-mentioned problems. It is in particular the object of the present invention to make it difficult to read a wireless tag for unauthorized persons. It is another specific object of the present invention to make it difficult to falsify wireless tags. It is still a specific object of the present invention to facilitate authentication and / or identification of the tag or related items. This object is achieved by a crypto-wireless tag according to claim 1, a method for operating at least one wireless tag according to claim 6 and a wireless cryptosystem according to claim 16. Advantageous embodiments can be taken from the dependent claims.

The crypto-wireless tag contains a readable record, which comprises at least one crypto data block. The form of the data set is irrelevant at first and is not limited to standardized formats. The data record can also be the crypto data block, ie have no further data blocks. The data record may comprise a plurality of crypto data blocks with different functions and / or keys. Crypto data block is understood to mean a range of data which has at least one cryptographic key to it

Encrypting, decrypting or identifying (eg for digitally signing) data is assigned, d. H. includes such a key and / or includes an indication of where such a key is provided.

First, a crypto-wireless tag can be individually identified and authenticated by polling the key, whereby the key, e.g. As a digital signature, due to its cryptographic nature can not be easily made or corrupted. Second, alternatively or in combination, the key may be used to encrypt all or part of the further data set so that only the authorized access user can read or write the encrypted data. Since the keys do not have to be entered like a password each time, the cryptographic methods can be carried out simply and quickly, possibly fully automatically.

Any form of wireless tag can be used. The crypto-wireless tag is more advantageously compliant with one or more standards, such as those outlined above. This can be done for example by the assignment of a free (sub) field on the day by the key or key hint.

It may use any appropriate key method for

Decrypting data and / or signing or

Authentication or verification can be used.

The crypto data block can be used for faster detection or

Label as such a crypto-qualifier assigned. A crypto qualifier is a string that indicates the presence of a crypto-data block. The crypto qualifier can be a separate data block or part of the crypto data block.

It is advantageous for the direct application of the cryptography method if the at least one crypto-data block-that is, one crypto-data block or at least one of a plurality of crypto-data blocks-comprises a cryptographic key, since thus obtaining the key belonging individually to the wireless tag from outside the reference can be omitted. The key can also be distributed over several crypto data blocks.

It is advantageous for mitigating unauthorized reading and altering if at least one other data block is encrypted based on the at least one crypto data block, if desired including another crypto data block. This way, manufacturer information, product IDs, expiration dates, etc. can be protected against unauthorized access.

It is advantageous, inter alia, for the use of secure and widespread key methods, if a 'public-key method' involving a one-way crypto-key pair is used, which is also referred to as a public key ('Public Key') and private key ('Private Key', 'Secret Key'). Known, advantageous examples of encryption for use in a crypto-wireless tag are based on the international standard OpenPGP (RFC2440) or PGP. Especially preferred is the GNU Privacy Guard (GnuPG) encryption program developed by the GNU Privacy Project (GnuPP).

These asymmetric encryption methods can, for. B. are applied when the at least one crypto data block includes the public key. The private / secret key is advantageously stored on a special keyserver, eg. B. at the manufacturer or in a trust center.

Of course, other - symmetric and asymmetric - key methods with corresponding keys can be used. The encryption method is not restricted, so it can be based on the same or different encryption algorithms or programs, such as general RSA encryption, SSL, SSH, SHA-I, MD-5, various Huffman methods, etc.

The key or key pairs can also be used as

One-Time-Pads (OTPs), analogous to the PIN / TAN-method for online banking.

It can also be applied on a wireless day and digital signatures data keys simultaneously; so the signature can be encrypted at the same time etc.

The object is also achieved by a method for operating at least one crypto-wireless tag, in which at least one crypto-data block is read out by means of at least one reader and at least one cryptographic method using at least one the at least one Krytodatenblock assigned key is performed. Assigned here means that the key is either present in the crypto data block - and possibly still needs to be extracted - or that the key can be obtained through a linked access. By the cryptographic method can, for. B. depending on the nature of the tag, the decoding or encoding and the key type, an encryption and / or decryption are performed or a digital signature to be verified.

In this case, a suitable infrastructure is required, the z. For example, secure data lines (eg, SSL encrypted), databases (eg, on special cryptoservices), devices (eg, access secured and overdeleted), programs (eg, access protected), etc. may be included.

Particularly advantageous, especially for the use of asymmetric key methods, when performing the cryptographic method by means of an asymmetric key method, such as an RSA-based method such as PGP or GnuPG, etc., where at least one of the crypto-data blocks of the tag comprises a public key, and the at least one external crypto data block comprises a secret key.

For the secure execution of the method, it is favorable if the further, external crypto data block originates from a crypto database, in particular if this is part of a trust center or specially secured area.

To protect against unauthorized reading of the tag data set, it is also an advantage, if only by performing the cryptographic method at least one other data block - u. Also, another crypto-data block - the crypto-wireless-tag, which has been encrypted on the basis of the at least one crypto-data block, is made unencrypted readable. In this case, it does not matter which instance (eg, a program or the end user) makes the data readable, or on which layer (s) (see description of Figure 1) the cryptographic method is performed.

For quick and easy authentication, it is favorable if, by using the cryptographic method, the at least one crypto-wireless tag signature contained on at least one crypto-data block is verified.

It is also advantageous for operating the method if the application of the cryptographic method in the reader, in a downstream external crypto-client or crypto-module (corresponding to a crypto-program component, hereinafter referred to as crypto-module) - here : a hardware or software implemented own device to perform the key procedure - and / or middleware, e.g. B. at the so-called. "Point-of-Sale" / PoS happens. The crypto-client or the crypto-module can also be integrated in the read / write device or in other programs, in particular the middleware, wherein a response of the crypto-client or module then conveniently takes place via its own application programming interface (API).

In particular, for easy and fast reading of tags, in particular when using encrypted and normal wireless tags, it is advantageous if in the event that the reader initially does not recognize the presence of the at least one crypto data block when reading the wireless tag, depending the read error message configures the reader to recognize the at least one crypto data block, and the reading is repeated at least once. "Reading" in the above-described method is also understood to mean writing data, the reader (or reader / writer) now being set up to write the data; and the above method is appropriately reversed in an appropriate amount; For example, instead of decryption, encryption must be performed before the writing device (or reading / writing device) is actuated.

The method also includes combined reading and writing steps.

The object is also achieved by a wireless cryptosystem comprising at least one read device (or writing device for writing) of the at least one crypto data block of a crypto-wireless tag, furthermore a data line to a crypto-database, and a device for performing the cryptographic Method using at least one crypto-data block of the crypto-wireless tag and an external crypto-data block, which can be supplied by the crypto-database, the device for

Implementation of the cryptographic method for receiving the crypto-data block of the crypto-wireless tag and for receiving the external crypto-data block is set up. Depending on the operating mode (read / write) z. For example, unencrypted data may be output to a middleware, or encrypted data may be sent to the writing instrument.

The wireless cryptosystem is particularly advantageous if the device for performing the cryptographic method as - hardware or software-implemented - crypto-client or crypto-module exists, the z. B. is implemented in the read / write device and / or integrated in a downstream of the reader stand-alone form (eg, a dongle or a crypto-box) and / or in a middleware. When integrated into other programs, the crypto module z. B. be addressed via APIs or as a subroutine. Of course, a wireless cryptosystem is also included, which instead of or additionally is not only equipped for reading and decrypting data stored on the crypto-wireless tag, but also for encrypting and writing data to the crypto-wireless tag.

In the following exemplary embodiments, the invention is described schematically in more detail.

FIG. 1 schematically shows a layer model ("layer model") of the data process of a wireless tag;

Figure 2 is a sketch of a read / write method of a conventional wireless tag according to the prior art;

FIG. 3 shows variants of the operation of the crypto-wireless tag in its subfigures 3 (a) to 3 (d).

FIG. 1 shows a layer model of wireless tags.

Layer 1 is the physical layer and defined by the specification for the different wireless tags. This layer describes how data is physically written and read on a wireless tag.

Layer 2 is the encoding layer. This layer describes how the data stream written to a wireless tag or read by a wireless tag is structured, including, among other things, which information fields it contains and how these fields (the data of these fields) are written by appropriate readers , and / or the middleware software is interpreted. Layer 2 may include the encoding schemes of known standards such as EAN and others. This layer will largely support backward compatibility for the currently existing ones Used encoding schemes. Basically, it is possible to define new encoding schemes, as far as they are not in conflict with the existing encoding schemes, so that the consistency of existing encoding standards is preserved. The terms "encoding" and

Thus, "decoding" does not refer to cryptographic methods and thus should not be confused with the terms "encryption" or "decryption".

Layer 3, called User Data Layer, contains freely definable data. This layer 3 can include both character data and numeric data. In general, Layer 3 can contain any type of data a user wants to write on the wireless tag. Of course, this must be based on the existing

Memory limitation are respected. The data in layer 3 need not be stored in a structure defined in a standard, and therefore must be controlled by software and / or hardware instances above it. There is no interpretation of the data in this layer.

Layer 4 represents the data-interpreting instance and is called an application layer. This is a suitable infrastructure (software and / or hardware), which has the information how to interpret the data from Layer 2 and / or Layer 3. Layer 4 receives and produces data and processes them accordingly. B. by the user, usable data. This may be a software application, e.g. For example, a (sub) program, a device driver, or any resource serving Layer 3.

The process through the layers is accomplished by traversing layers from a higher layer to a lower layer, or vice versa. Each layer is independent of the other, and each layer provides an interface for data exchange. This is necessary to, for example, the Architecture of devices, such as readers, or software applications to define. If z. For example, if there is a wireless tag reader designed for reading Layer 2, the software for the reader must be Layer 2 compliant software to achieve full functionality across the layers.

In this layer model, crypto technology can now be applied to Layer 2, Layer 3 and Layer 4 (see "Lock" icon).

In this figure, for ease of illustration, no distinction is made between encryption, decryption of information, and digital signing of information and the wireless tag itself.

It can be distinguished on which layer the encryption or decryption takes place, and which of the information stored on a wireless tag is subject to encryption. This means that all or part of the stored data is subject to encryption (here: encryption, decryption or a digital signature).

For encryption and decryption of data on crypto-wireless-tags basically all known crypto-key-methods can be used. It is for implementation and z. B. the structure of the infrastructure cheap to use widespread key method as z. B. for the encryption and decryption of emails. For this purpose, state-of-the-art cryptographic technologies can be used, such as PGP (Pretty Good Privacy) or GnuPG encryption programs or encryption algorithms. Here, a limited or unlimited bitstream goes through one

Encryption process and is transformed into an encrypted bitstream. As it is still on wireless tags these days If there is a limitation in the memory capacity, the encrypted bit stream can be adapted to the size of the physically available memory space. As a consequence, the amount of storable data is limited by the physical layer 1.

Today's crypto technology, in combination with an appropriate infrastructure, allows crypto key pairs to be used as digital signatures or identification keys on wireless tags, against which a

Authentication can be performed. This digital signature or key can be used to identify and / or authenticate wireless tags, and thus also the item associated with that tag. Furthermore, the digital signature or the identification key can be used as an index to a data source, which can provide more information. Digital signing has the advantage that you can work with fixed bitstream lengths. Each crypto key used for this method has a defined length that depends on the encryption mode used (for example, 64-bit or 2024-bit crypto keys). Should the bit-stream length of the key used exceed the bit-stream length specified by the physical layer 1, compression algorithms may be applied to adjust the bit-stream length of the crypto-key. On a crypto wireless tag, you can also have multiple data blocks with multiple functions, such as: As encryption and signature, be applied.

The underlying infrastructure may be made wholly or partially open to the public, or may be wholly or partially limited to instances.

The data set stored on the wireless tag has the general structure, possibly dependent on the respective layer {Bl I B2 I ... I KBl | Bi | Bi + 1 | KB3 | ...}

on with Bl, B2, ..., Bi, Bi + 1, ... general data blocks and KBl, KB2 crypto data blocks. The number, length and order of the data blocks can be adjusted as required. For example, KBl may be a public key, KB2 may be a digital signature, etc. The general data blocks Bl, B2, ..., Bi, Bi + 1, ... may be partially or completely encrypted themselves or not encrypted as a whole. Data blocks can be defined on each layer.

Figure 2 shows in outline a read / write method of a conventional, unencrypted wireless tag according to the prior art.

A wireless tag 10 with an encoding scheme but no encryption is used. The data of the wireless tag 10 are read out by means of a reading device 20 and processed by a middleware 40. The middleware 40 -z. As an administration program based on SAP o. Ä. - Processes the data to information that for the end user (indicated here by figures) have a meaningfulness. This end user could, for example, be a seller, transporter, dealer, customs official or end customer. The encoding, ie the implementation of information on a higher-level layer, happens in this figure behind the reader 20, possibly also by a unit integrated in the reader or software, and then in a further stage before the end user (the En- or Decoding is symbolically indicated by the cogs).

Writing information to wireless tag 10 is reversed by this procedure. In this case, no reader 20, but to use a corresponding writing instrument, preferably a combined read / write device 20; instead of encoding, decoding is used. There is no encryption or decryption in the process described here.

Figure 3a schematically shows a method for reading and / or writing a ^• crypto-wireless tags. 1

The reader or writer 20 has the function of encrypting or encrypting wireless tags 1. For this purpose, the reading or writing device 2 is connected to a suitable infrastructure, which provides him with the appropriate information necessary to encrypt or decrypt the wireless tags 1. In this figure, the infrastructure comprises a crypto database 5 with which

Decrypting necessary information such as a secret key. The database can be part of the infrastructure, eg. B. a corporate network, be or be connected to this functionally, z. B. as an independent trust center, which is connected via a data connection to the corporate network.

In this figure, therefore, encrypted data are read from the reading device 2 during reading, decrypted by means of the public key contained on the tag and the secret key of the crypto database 5 and then further processed as usual, ie decoded or encoded here.

FIG. 3b schematically shows another method, similar to FIG. 3a, for reading and / or writing the crypto-wireless tag 1.

Here, a corresponding instance is inserted between the reading or writing device 2 and the middleware 4, which is referred to as a crypto-client or crypto-module 3. In this variant, the data are not sent directly from the reading or writing device 2 to the middleware 4 or vice versa, but pass on this way the crypto-client or - module 3, which performs the encryption or decryption. The crypto-client or module 3 is connected to a suitable infrastructure, in this case with a database 5, which provides him with the corresponding information necessary for encrypting or decrypting the data, eg. B provides the public key.

FIG. 3c diagrammatically shows another method, similar to FIGS. 3a and 3b, for reading and / or writing the crypto-wireless tag 1.

This variant is very similar to the variant in Figure 3b, except that here the crypto-client or the crypto module. 3

Part of the middleware 4 is. The middleware 4 itself, z. As an SAP program or other management software, has an application programming interface (API), which can be used by a suitable infrastructure, which the corresponding information that is required for encryption and ^■ decrypt the data, here from a Crypto database 5 provides.

FIG. 3d schematically shows another method similar to FIGS. 3a to 3c for reading and / or writing the crypto-wireless tag 1.

In this variant, the crypto client / module 3 is located for encryption or decryption between middleware 4 and the end user.

The above-listed and other suitable methods of operating the crypto-wireless tag 1 may be used in a variety of applications not limited by this description. Here are some application scenarios and application examples. 1. Use of encryption

Privacy Protection Using current wireless tag technology, privacy protection is not guaranteed; Unauthorized third parties can access information sent by the unencrypted wireless tag. When using crypto-wireless tags, unauthorized reading of information is partially or completely excluded. The following examples are given from a multitude of possible application scenarios for crypto wireless tags:

(i) Retail In the future, retail products may be tagged with crypto-wireless tags. This facilitates the billing at the cash register, since the purchase can be detected by readers and the bill is created. Access to the product data should be limited to the seller and the buyer. For unencrypted data, an unauthorized third party - eg. B. by means of a secret attached own reader - obtain information about prices and number of purchased products. This in turn allows conclusions about product sales, pricing and purchasing behavior. This can be prevented by using crypto wireless tags.

(ii) Biometric Data - Diagnostics Human samples sent by physicians to laboratories are currently provided with the patient information and the test assignment in plain text. To protect this information from unauthorized third parties and to avoid sample confusion, the samples can be provided with crypto-wireless tags. (iii) Baggage Carriage on Air Travel On national and international air travel, baggage is tagged with barcode labels identifying the departure and destination, the flight number and the name of the passenger. Since it can be expected at certain destinations that a higher quality case content is present, there is an increasing number of thefts. Here one could, in order to protect the personal flight information, instead of the barcode labels use future wireless tags.

2. Using the Digital Signature

Guarantees of Origin - Certificates of Authenticity Today, cross-industry significant economic damage is caused by illegally manufactured, falsified or copied products. Crypto-wireless tags bearing a digital signature allow a one-to-one certificate of authenticity to be maintained at the product level. This is done by linking digitally signed crypto-wireless tags with a suitable infrastructure, for example a hierarchical trust center, as an authentication instance. From one

Numerous possible application scenarios for crypto-wireless-tags are given the following examples:

(i) Counterfeits, counterfeits, branded items, original spare parts, pharmaceuticals, money and identity cards, etc. are provided with digitally signed crypto-wireless tags. As a result, the manufacturer and the uniqueness of the article is clearly detectable. Assuming a suitable infrastructure, another article with the same characteristics is clearly recognizable as a forgery. (ii) copyright protection

To prevent the illegal copying of copyrighted content on digital media, there are currently few suitable options. By linking a digital media containing copyrighted content to a crypto-wireless tag and the appropriate infrastructure, illegal duplication will be rendered inoperable.

Claims

claims

First crypto-wireless tag (1) with a contained therein record, characterized in that the record comprises at least one crypto data block (KBl, KB2).

2. crypto-wireless tag (1) according to claim 1, wherein the at least one crypto data block (KBl, KB2) comprises a cryptographic key.

3. crypto-wireless tag (1) according to claim 2, wherein at least one other data block (Bl, B2, Bi, Bi + 1) on the basis of the at least one crypto data block (KBl, KB2) is encrypted.

4. crypto-wireless tag (1) according to any one of claims 2 or 3, wherein the at least one crypto data block (KBl, KB2) comprises a public key of an asymmetric encryption method.

5. crypto-wireless tag (1) according to any one of the preceding claims, wherein the at least one crypto data block (KBl, KB2) comprises a signature.

6. Method for operating at least one crypto wireless tag (1) according to one of the preceding

Claims comprising at least the following steps:

(a) reading at least one crypto data block (KB1, KB2) of the crypto wireless tag (1) by at least one reader (2); (b) performing a cryptographic method using at least one key assigned to the at least one crypto data block (KBl, KB2).

^. Method according to Claim 1, in which the cryptographic method is carried out by means of at least one further external crypto data block (KB3).

?. The method of claim 1, wherein the further, external crypto data block (KB3) of a. , Crypto database (5) comes, especially if this one

^{■ is} part of a trust center.

9, Method according to one of claims 1 or i, in which

- Performing the cryptographic method by means of an asymmetric key method, in particular an RSA method, in particular by GnuPG happens, wherein

- At least one of the crypto data blocks (KBl, KB2) comprises a public key, and

- The at least one external crypto data block (KB3) comprises a secret key.

'C-. Method according to one of claims T- to \ 9 ,, in which, by performing the cryptographic method, at least one other data block (Bl, B2, .Bi, Bi + 1) of the crypto-wireless tag (1) based on .the Base of the at least one crypto data block (KBl, KB2) is encrypted, made unencrypted readable.

U. A method according to any one of claims T- to ^ ⁰ , in which by performing the cryptographic method on at least one crypto data block (KBl, KB2) contained at least one signature of the crypto-wireless tags (1) is verified. Method according to one of claims 7 to 7, in which the cryptographic method is carried out in the reader (2), in a downstream crypto-client or crypto-module (3) and / or in a middleware (4).

V}. Method according to one of claims T to VV., Wherein, in the event that the reading device (2) when reading the crypto wireless tags (1) the presence of the at least one crypto data block (KBl, KB2) initially not detects, in response to the output error message, the reader (2) is configured to recognize the at least one crypto data block (KBl, KB2), and the reading is repeated at least once.

IH .. Method according to one of claims 7 to 13, wherein a

Reading the crypto-wireless-tag (1) is replaced by a corresponding write of the crypto-wireless-tag (1).

'S ^' , wireless cryptosystem with a reading device (2) for reading out the at least one crypto data block (KB1, KB2) of a crypto wireless tag (1) according to one of the claims 1 to &^'' ,

a crypto database (5) with an external crypto data block (KB3),

- An apparatus for performing a cryptographic method based on at least the crypto data block (KBl, KB2) of the crypto wireless tag (1) and the external crypto data block (KB3), wherein

- The apparatus for performing the cryptographic method for receiving the

Crypto data block (KBl, KB2) of the crypto wireless tag (1) and configured to receive the external crypto data block (KB3).

id. A wireless cryptosystem according to claim 1, wherein the apparatus for performing the cryptographic process is in the form of a hardware and / or software-implemented crypto-client or module (3) integrated in the reader (2), and / or - is independent and / or integrated in a middleware (4), preferably via an API.

H: . A wireless cryptosystem according to claim (f or Ib) adapted to write cryptographic data to the crypto wireless tag (1).