While designers of cryptographic algorithms are rarely considered as potential adversaries, past examples, such as the standardization of the Dual EC PRNG highlights that the story might be more complicated. To prevent the existence of backdoors, the concept of rigidity was introduced in the specific context of curve generation. The idea is to first state a strict scope statement for the properties that the curve needs to have and then pick e.g. the one with the smallest parameters. The aim is to ensure that the designers did not have the degrees of freedom that allows the addition of a trapdoor. In this paper, we apply this approach to symmetric algorithms. The task is challenging because the corresponding primitives are more complex: they consist of several sub-components of different types, and the properties required by these sub-components to achieve the desired security level are not as clearly defined. Furthermore, security often comes in this case from the interplay between these components rather than from their individual properties. In this paper, we argue that it is nevertheless necessary to demand that symmetric algorithms have a similar but, due to their different nature, more complex property which we call “unswervingness”. We motivate this need via a study of the literature on symmetric “kleptography” and via the study of some real-world standards. We then suggest some guidelines that could be used to leverage the unswervingness of a symmetric algorithm to standardize a highly trusted and equally safe variant of it.
|Title of host publication||SSR 2019 - Proceedings of the 5th ACM Workshop on Security Standardisation Research Workshop|
|Publisher||Association for Computing Machinery|
|Number of pages||12|
|State||Published - 11 Nov 2019|
|Event||5th ACM Workshop on Security Standardisation Research Workshop, SSR 2019, co-located with the 26th ACM Conference on Computer and Communications Security, CCS 2019 - London, United Kingdom|
Duration: 11 Nov 2019 → …
|Name||Proceedings of the ACM Conference on Computer and Communications Security|
|Conference||5th ACM Workshop on Security Standardisation Research Workshop, SSR 2019, co-located with the 26th ACM Conference on Computer and Communications Security, CCS 2019|
|Period||11/11/19 → …|
Bibliographical noteFunding Information:
The authors thank the anonymous reviewers for their insights and suggestions and John Kelsey for shepherding this submission. The first author was supported in part by the Israel Ministry of Science and Technology, the Center for Cyber, Law, and Policy in conjunction with the Israel National Cyber Bureau in the Prime Minister's Office and by the Israeli Science Foundation through grant No. 880/18.
© 2019 Copyright held by the owner/author(s). Publication rights licensed to ACM.
ASJC Scopus subject areas
- Computer Networks and Communications