Master Thesis
Physical attacks and code-based cryptosystems
For one or two student(s)
Domain
Cryptography, coding theory and secure implementation
Presentation
Most of the cryptographic schemes used and studied today are based on number theory problems as factorisation or discrete logarithm. In 1994, Shor proposed an algorithm which can factorise in polynomial time using a quantum computer. So RSA and several others schemes are threatened by the quantum computer.
Code-based cryptography is one of the branches of post-quantum cryptography with lattice- based, multivariate-based and hash-based cryptography. Schemes based on problems as syndrome decoding or decoding random codes are well studied for years and there doesn't exist polynomial time algorithm to solve those problems even in a post quantum world. McEliece was the rst to propose a code-based cryptosystem and several improvements and derivation have been proposed so far.
To consider the use of code-based cryptosystems in the real life, they must be resistant to physical attacks as power analysis or fault injection.
To date, the study of such attacks on such schemes are rare and there is a lot of work to do in this area.
Purpose
After a state of the art of code-based schemes and side-channel attacks the student will imple- ment an attack even on smart card, graphic card or CPU. Both practical and theoretical, this thesis proposes to study the physical attacks also called side-channel attacks like Simple Power Anal- ysis, Dierential Power Analysis, Higher-Order-Dierential Power Analysis or Fault Attack and show how we can apply these patterns to attack code-based cryptosystems like Courtois-Finiasz- Sendrier signature scheme, Stern's zero-knowledge identication scheme or McEliece public key cryptosystem.
The CASED building has a laboratory for the implementation and the application of the attacks.
The student will have to write an article on his research in a LATEX format and give an english presentation to the team. With specialists in physical attacks and code-based cryptography, the student could work with dierent teams and improve his background in the two areas.
Goals
The outcome of the thesis is supposed to be a publishable result on physical attacks on code-based cryptosystems.
Required Skills
The required skills, in order of importance, are:
High motivation and creativity;
Skills in C;
Good knowledge of cryptographic constructions;
Experience with reading research papers.
Knowledge of the English language goes without saying.
Bibliography
[1] - Falko Strenzke, Erik Tews, H. Gregor Molter, Raphael Overbeck, Abdulhadi Shoufan: Side Channels in the McEliece PKC. PQCrypto 2008: pages 216-229.
[2] - P.-L. Cayrel, P.Gaborit and E. Prou: Secure Implementation of the Stern Authentication and Signature Scheme for Low-Resource Devices CARDIS 2008: pages 191-205.
Institute
CASED : www.cased.de
Place : Darmstadt, Germany (4h30 from Paris by train)
Team : Cryptographic primitives
Master thesis supervisor : Dr. Pierre-Louis Cayrel Laboratory director : Pr. Johannes Buchmann
Contact
If you are interested, please contact Dr. Pierre-Louis Cayrel (french speaker) CASED : Center for Advanced Security Research Darmstadt
Mornewegstrasse, 32 64293 Darmstadt Germany
Phone: 0049-6151-16-64821
e-mail supervisor: [email protected]
e-mail laboratory director: [email protected]
web : http://www.cayrel.net/
