Untitled CONCLUSIONS

Conclusions

Given commonly discussed security threats for an RFID system, and the available security measures against these threats, we can evaluate their implementation on RFID. This means incorporating (a qualitative estimate of) the costs of each security measure and on the other hand (a qualitative estimate of) the costs of performing a specific attack (BSI 2004). The comparison of these two types of costs will give insight into the current vulnerabilities of RFID systems. 

The summary of this evaluation is shown . The qualitative estimates of the costs are explained in the following sections, followed by a separate section of conclusions.

Table : Summary of security evaluation

From a financial point of view, the most alarming risk would be the risk that has low costs for performing the threat and high costs for taking countermeasures. By only analysing , this would be the risks of deactivating or detaching the tag because these are fairly easy to perform and countermeasures are more involved. Although much attention in the media is paid to eavesdropping on the air interface because of the privacy consequences of the consumer, from a security cost point of view indeed the vulnerability of the tag itself is an often overlooked aspect. Since tags are easily removed or destroyed, and countermeasures are costly, this can be seen as the weakest point of an RFID system.

At first sight it seems that a redesign of tags might be needed to overcome these risks. However, some important considerations have to be taken in mind: 

• These are the results of a general threat analysis and rough cost estimation. No conclusions can be drawn with respect to specific applications or scenarios. Each application or scenario would require its own more detailed and specific security analysis. The (seriousness of the) consequences of removing or destroying RFID tags depend on the application. Depending on the business case of the application, even a Common Criteria accreditation process might be worthwhile. 

• The costs are not the only point of view. Also user convenience, user’s acceptance, interoperability, etc. are important factors to take into account. This would require a case by case analysis. 

• The RFID system is usually part of a larger IT system which includes the back-office. Since the security chain is as weak as the weakest link, we have to consider the entire IT system.  

The next chapter gives an overview on common areas of application for RFID.