1. Autonomous and Intelligent Healthcare System (SYSIASS) Activity 2 Progress April 2011 Part-financed by the European Regional Development Fund

2. Overview Technology to address issues preventing remote healthcare Two major strands  FSS: Utilise wireless communications technology via Frequency Selective Surfaces  ICmetrics: Secure data via encryption based directly on system properties

3. Current Progress ICmetrics  Initial investigation commenced  Collaborative visit Essex-Kent FSS  General principles established One invited publication to date

4. ICmetric Encryption Encryption message cipher Key Conventional encryption system Encryption message cipher Key Key Generator ICmetric ICmetric encryption system

5. What exactly is the problem? Encryption  Symmetric key requires key storage and key exchange  Asymmetric encryption requires the private key to be stored in some fashion  Compromising the key compromises all systems protected by the key

6. So what is the proposal? Generate a unique identifying number directly from features associated with the circuits and software associated with the wheelchair Features are properties of a sample which can be used to distinguish it from peers A significant number of features are required as it is necessary for the basis to be sufficiently large to form a significant hurdle to a code- breaking attempt. Significantly:-  Features which vary may be employed

7. So how do you address the problem?  Normalise features using sample means and variances (or more generally distributions)  Feature quantisation: quantisation intervals dynamically determined by feature mean and variance  Feature correlations act against us: de-correlation strategy  Feature combination: weighted strategy employed  Redundant contribution: removing “common” components and “random noise” components  Key Generation: Use as basis for generating two primes (for e.g. RSA encryption)

8. Independent feature distribution Possible distribution of address data transaction for four different circuits (M1-M4).

9. Multi-Modal feature distributions common Two circuit system (C1,C2) for each of which one feature (F1) is measured.

10. Ideal Non-Ideal Keyspace Probability (P) But can you break the key? : Key Distribution

11. Summary Generate the encryption keys directly from the ICmetric sample Advantages of direct encryption  if key directly from a ICmetric sample:- Template of sample never stored (Private) key never stored  New sample required to decrypt (unless cipher broken)