Algorithm Substitution Attacks on Symmetric Encryption Schemes.

Lead Research Organisation: Royal Holloway University of London
Department Name: Information Security

Abstract

Since the Snowden revelations, there has been an increased recognition that the threat of mass surveillance targeting regular users' communication is a realistic concern. This project examines how symmetric encryption schemes can be subverted to undermine users' confidentiality while evading detection, continuing a line of enquiry that was re-initiated by Bellare, Paterson and Rogaway in 2013. The project looks at the definitions and assumptions used in the current literature and aims to relate that analysis to the way that encryption schemes are commonly used in internet protocols at present.

Planned Impact

The most significant impact of the renewal of Royal Holloway's CDT in Cyber Security will be the production of at least 30 further PhD-level graduates. In view of the strong industry involvement in both the taught and research elements of the programme, CDT graduates are "industry-ready": through industry placements, they have exposure to real-world cyber security problems and working environments; because of the breadth of our taught programme, they gain exposure to cyber security in all its forms; through involvement of our industrial partners at all stages of the programme, the students are regularly exposed to the language and culture of industry. At the same time, they will continue to benefit from generic skills training, equipping them with a broad set of skills that will be of use in their subsequent workplaces (whether in academia, industry or government). They will also engage in PhD-level research projects that will lead to them developing deep topic-specific knowledge as well as general analytical skills.

One of the longer-term impacts of CDT research, expressed directly through research outputs, is to provide mechanisms that help to enhance confidence and trust in the on-line society for ordinary citizens, leading in turn to quality of life enhancement. CDT research has the potential of directly impacting the security of deployed system, for example helping to make the Internet a more secure place to do business. Moreover the work on the socio-technical dimensions of security and privacy also gives us the means to influence government policy to the betterment of society at large. Through the training component of the CDT, and subsequent engagement with industry, our PhD students are exposed to the widest set of cyber security issues and forced to think beyond the technical boundaries of their research. In this way, our CDT is training a generation of cyber security researchers who are equipped - philosophically as well as technically - to cope with whatever cyber security threats the future may bring. The programme equip students with skills that will enable them to understand, represent and solve complex engineering questions, skills that will have an impact in UK industry and academic long beyond the lifetime of the CDT.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/P009301/1 01/10/2016 31/12/2026
2045217 Studentship EP/P009301/1 01/10/2017 28/05/2022 Marcel Armour
 
Description Substitution attacks aim to replace an algorithm with a subverted version that behaves (almost) identically, but crucially differs in such a way as to leak information to a mass surveillance adversary who may be observing communication. We update existing definitions and introduce a new class of attacks that target the decryption algorithm of authenticated encryption schemes. We analyse an experiment running an implementation in python, which confirms the feasibility of the attack. We argue that this attack rep- resents an attractive opportunity for a mass surveillance adversary. Our work serves to refine the substitution attack model and contributes to a series of papers that raises awareness and understanding about what is possible with substitution attacks.
Exploitation Route Inform work looking at safeguarding privacy against potential adversary who seek to exfiltrate data from encrypted systems.
Sectors Digital/Communication/Information Technologies (including Software)