1. Advanced Information Security 6 SIDE CHANNEL ATTACKS Dr. Turki F. Al-Somani 2015

2. Module Outlines 2  Introduction to Side Channel Attacks  Simple Analysis Attacks.  Differential Analysis Attacks.  Types of Side Channel Attacks  Power Analysis Attacks Simple Power Analysis Attacks Differential Power Analysis Attacks.  Countermeasures  Summary

3. Introduction 3  Security Against Side Channel Attacks  Every computing device acts also as a source of additional information called side channel leak information  There are many side channel attacks in the literature Fault Data-dependent Power Consumed Operation dependent Data-and-operation dependent Execution time Data-and-operation dependent Magnetic field Operation dependent Data-and-operation dependent

4. 4 Introduction (Contd.)  Side Channel Attack (SCA)  Simple: a single observation  Differential: several observations used together with statistical tools.

5. 5 Examples of Side Channel Attacks  Time Attack  Power Analysis Attacks  Electromagnetic Radiations  Fault-Based (induced errors)  Processor-Flag (overflow or carry flag)  Hamming weight  Thermal Analysis

6. Simple Power Analysis Attacks 6  Security Against Side Channel Attacks (a) Power consumption trace of ECC scalar multiplication. (b) Power consumption trace of ECC point doubling operation.

7. Differential Power Analysis Attacks 7

8. Types of DPA Attacks 8  Refined Power Analysis (RPA) attacks:  Exploits a special point with zero-value such as (0, y) or (x, 0).  Zero-value Point Attack (ZPA):  A generalization of RPA where it exploits any zero- value auxiliary register.  Doubling Attack (DA):  Based on detecting when the same operation is performed on the same operands.

9. Types of DPA Attacks 9  Address-bit DPA (ABDPA):  Based on the idea that accessing the same location is correlated to the scalar bit value.  Projective Coordinates Leak (PCL):  Based on knowing the projective representation of a point obtained using a particular projective coordinate system.  More..

10. 10 ECC Scalar Multiplication

11. 11 SPA Countermeasures

12. 12 DPA Countermeasures  Randomization of the of the private exponent:  Each execution of the algorithm  Select a random No. and multiply it by the total No. of EC points (point at infinity O).  Add the result to d to have d’  Compute new Q multiplying d’ by P

13. 13 DPA Countermeasures (Contd.)  Blind the point P:  Add a secret random point R  S= dR  New Q will be computed by d( R + P )  Subtract S= dR to get dP

14. 14 DPA Countermeasures (Contd.)  Blind the point P:  Add a secret random point R  S= dR  New Q will be computed by d( R + P )  Subtract S= dR to get dP

15. 15 Countermeasures – Cont.  Randomized projective coordinates:  For new execution  or also after each point addition and doubling

16. PhD Thesis.. (2006) 16

17. Timing Attacks Paper (2006) 17

18. Power Analysis Attacks Paper (2008) 18

19. Survey Paper (2012) 19

20. Survey Paper (2012) 20

21. Another Survey Paper (2012) 21

22. Another Survey Paper (2012) 22

23. Buffer Paper.. (2013) 23

24. Patents 24  Turki F. Al-Somani, Method for Securing Scalar Multiplication aganist Simple Power Attacks, US 8,861,721 B2, 2014.  Turki F. Al-Somani, System and Method for Securing Scalar Multiplication aganist Differential Power Attacks US 8,804,952 B2, 2014.  Turki F. Al-Somani and M. K. Ibrahim, Method for Generic-Point Parallel Scalar Multiplication without Precomputations, US 8,755,517 B2, 2014.  Turki F. Al-Somani and Alaaeldin Amin, Method for elliptic curve scalar multiplication, U.S. 2012/0008780 A1, 2012.  Turki F. Al-Somani and Ayman Fayomi, Method for Efficient Postcomputation-Based Generic- Point Parallel Scalar Multiplication (submitted in Dec 2012).  Hilal Hussain and Turki F. Al-Somani, Method for Securing Elliptic Curve Cryptography against Simple Power Attacks. (submitted in Dec 2012).  Hilal Hussain and Turki F. Al-Somani, Method for Securing Elliptic Curve Cryptography against Differential Power Attacks (submitted in Dec 2012).  Turki F. Al-Somani, Method for Elliptic Curve Scalar Multiplication using Reference Points (submitted in May 2012).  Turki F. Al-Somani, Method for Method for Securing Scalar Multiplication agaanist Power Analysis Attacks using Reference Points (submitted in May 2012).

25. Summary 25  Resistance against DPA attacks can be achieved by combining two or more of the countermeasures proposed in the literature thus far.  To protect against the doubling attack, the projective coordinates should be randomized or a random field isomorphism should be used, while to protect against RPA and ZVP attacks, the base point P or the scalar multiplier k should be randomized.  Hence, to protect against all these recent DPA attacks, randomizing the scalar multiplier and randomizing the projective coordinates, for instance, can be applied together.

26. THANKS & GOOD LUCK Dr. Turki F. Al-Somani 2015