Security-Token

A security token ( simple tokens ) is a hardware component to identify and authenticate users. Occasionally, therefore software tokens are called.

The immediate possession of the token here is absolutely necessary in order to identify himself as an authorized user.

The terms electronic key or chip key, a token is also called.

If appropriate, other features are to be used for authentication against abuse, are possible, inter alia, the knowledge of a password or a PIN or biometric characteristics of the user. Security tokens can be personalized, they are then uniquely associated with a particular user.

4.1 High level of security
4.2 Low security
4.3 threats
4.4 Obstruction of manipulation
4.5 Discussion of solutions

Designs and technologies

The technical umbrella term token refers to all technologies used equally and does not depend on a particular aspect of the hardware. This includes all items that can save the information for the purposes of identification and authentication and transmitted.

Passive media

With smart cards, it also is token. USB tokens, which are connected to a USB port, have the advantages of a smart card without the need for a card reader.

There are also contactless token is used, see RFID. These so-called transponders can be integrated into key chains, smart cards and any other product as long as its properties do not interfere with the function. Thus the specific product itself becomes the token. The remote machine must be able to activate the token and read.

Common uses:

Vehicle and building key
Clothing, watches and jewelry
Implants in animals ( chipping )

There are also tokens with or without contacts, indicating a constantly changing and for a limited number of valid combination for the one-time password method (One- Time Password ( OTP ) generator ). Token and server compute these pseudo-random number at the same time. Thus, a unique authentication is possible. This number is generated, if also with a smart card in a portable reader. As additional safety features must be entered into the device is often a PIN and / or a request code. Example is the Sm @ rt- TAN procedure.

Trusted Platform Modules (TPM ) chips are similar to save a smart card private key. The chip is built-in in this case, but in a device, eg soldered to a computer motherboard. The whole unit is to the token. It is now possible to assign a clearly identifiable on the TPM device to a user. The TPM offering the possibility of securing access to the device ( pre-boot authentication ). Thus, ( indirectly) a authentication of the user to be made.

Active Media

There are also commercial devices, which operate as a token and transmit an authentication factor. For this, the communication between the device and the test equipment or workplace must be possible. Furthermore, it must be possible for secure authentication, for example, a bidirectional transmission.

Well-known examples are:

Mobile phones or smart phones, etc., with pin - Card to 3GPP standards
Active UHF transponder (RFID UHF active 868 MHz, all proprietary, no international standard ) or (RFID UHF active 433 MHz ISO / IEC 18000-7 or proprietary RFID microwave active 2.45GHz ISO / IEC 18000-4 or proprietary)
Active LF transponders (RFID LF active 128kHz, 134 kHz, all proprietary, no international standard )
Active RF transponder (RFID HF 13.56 MHz active, all proprietary, no international standard )
Galvanically coupled tokens (1 -Wire chips are no longer recommended for new designs )
Conventional smart cards according to ISO standards ISO / IEC 10536, ISO / IEC 14443 ( proximity card ), ISO / IEC 15693 ( vicinity card )
RFID NFC (Near Field Communication according to ISO 18092, ISO 21481, etc.)

Needs to each individual workstation to be connected to a special testing device ( RFID standard or proprietary solution) or an interface (1- Wire).

By contrast, when using Bluetooth V4.0 the necessary infrastructure in all modern PCs, PDAs and smartphones contain ( probably from 2011Q2 ). The smart phone then operates as a smart agent from an autonomous inspection process that requires no operator action for simple authentication.

Well-known examples are:

Mobile phones or smart phones etc. with Bluetooth interface IEEE 802.15.1 ( Bluetooth V4.0 function standard protocols 2.45GHz with various standard profiles )
Special Bluetooth token ( function Bluetooth V4.0 protocol stack Low Energy 2.45 GHz)

Applications

Security tokens usually come as a (user ) certificates for secure transactions used:

To log on to workstation (company or government ) networks, such as a Windows domain
The utilization of Internet services, particularly as HBCI card for online banking
As a key container for data and e- mail encryption and digital signatures
As access authorization and identification (eg, company ID, e- passport, car keys )
For Time & Attendance
As a SIM card in mobile phones
As cash and / or debit card at ATMs and customer terminals (eg, phone)
As an access card to pay- TV services
As a bank card, usually in the unit with the money card, the use of ATMs and payment terminals
As health insurance card; the (future) Electronic Health is used as a token for access to a data network
As tickets and tickets
As a security module for unique identification, for example, Trusted Platform Module
The digital rights management; here the right to use data (software, music, e -books, ...) is possibly linked to the hardware, see also copy protection dongle

In general, decentralized systems in which data was stored on the token itself, and more often replaced by networked systems, where the token is used only as identification.

By the editors of the token several functions are preferably integrated into a token to "add value " by the use of the token to reach and create comprehensive utilization and movement profiles.

Authentication process (schematic)

Security, forgery, tampering

For safety- critical applications, a security token must be a single article which is specially protected against tampering and duplication or fraud.

High Security

The security token must generate keys that can be used exactly once. This is not possible with fixed key, but only with ad hoc generated keys. For this purpose, a circuit may be molded in plastic and safety mechanisms, such as those used in smart card chip are protected against reverse engineering. For this purpose, cryptographic methods are used. The cryptographic operations then take place within these chips so that the keys can not be read repeatedly. The authenticity of the token and its single-use key must be checked automatically.

Low security

Also, methods which only allows identification but no authentication will be used in practice for authentication. A code of such tokens is not tamper-proof, as the identification feature can be read and copied freely. These methods include, inter alia solutions with passive RFID chips that have a unique serial number and are designed according to various ISO standards for use in electronic labels ( tags).

Uncertainty within the meaning of copied are pure storage solutions with smart cards, magnetic stripe cards, bar codes, key files on media like USB sticks and the classic key.

Hazards

An attack can also be done on the communication between a ( otherwise secure ) token and the reader, in the simplest case of a replay attack. Free access ( USB ) connection lines allow easy intermediate switching of data loggers. In particular, if no mechanical and / or optical control of the token is carried out by the reading device or operator, and devices can be used that do not need to be similar to the original token in the type and size of the system to overcome. Radio transmissions can often still recorded at a great distance, thus providing a large contact surface for manipulation

Disability of manipulation

A completely secure solution there will never be a single factor authentication, each backup method can be overcome. The design of the token and the type of ( mechanical, electrical, magnetic, optical, ...) data transfer has a major impact on the protection against manipulation. A smart card may be, for example, fully retracted and shielded by a reader. Likewise entrusts the execution of a reader or customer terminals as a compact, against theft, exchanges and other manipulation -protected unit significantly to safety.

Discussion of solutions

The distinction between the use cases is an obvious prerequisite for evaluation of safety, for example:

Access control from the public space
Access Control in Public Space
Access control in a well secured area
Access control with good separation from the environment

All applications in the public space are inevitably compromised by unauthorized third parties. Claims to the contrary rely on restrictions that are often not explicitly mentioned, for example, the maximum usable reading distance. The convenience of handling is always accompanied by threats. Generalizations are not helpful.

Advantages and Disadvantages

At least one additional authenticating feature is used, such as PIN.
The token is in fact unique and can not be copied or manipulated at see skimming debit cards and credit cards
The token can be in case of theft or loss blocked in the system in order to avoid unauthorized use
Tokens can be used with remote procedure covered

A token as the sole authentication feature without second independent authentication feature does not provide reliable protection against manipulation, loss or attacks;
The use of token causes like any technical solution costs for the manufacture, registration and / or personalization, distribution and the provision of infrastructure in the form of test or readers and software;
The token may be destroyed or lost, and then temporarily exclude the user of important functions of daily life or professional activity;
The token, and thus its user, is always uniquely identifiable: a release of access for anonymous users is not provided due to lack of security.

Possession (law) Biometrics ISO/IEC 14443 Electronic Cash Challenge–response authentication Credit card fraud#Skimming

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