A privacy-preserving solution for tracking people in critical environments

In critical environments a high level of security and safety is required, leading to the necessity of controlling as much as possible physical access and localization of people. An effective possibility for tracking people is based on the use of RFIDs, in such a way to have logs reporting people localization at any time. This way, the (a-posteriori) analysis of logs can provide decisive information in case of a security/safety incident. Unfortunately, in most cases, a similar solution is intolerable for privacy reasons, so that finding a good solution of the trade-off between people privacy and security/safety requirements assumes a very important role. This paper proposes an RFID-based technique to trace people but introducing a certain degree of uncertainty, in such a way that their privacy is fully preserved. This approach implements the k-anonymity property for which we are able to guess who accessed a place, at a given time, with probability k-1. An important aspect of our technique is that it is implementable via very cheap RFID tags, thus making our proposal really concrete and attractive. The experimental evaluation shows the capability of the proposed method to reach the aimed results.