Short-Lived Forward-Secure Delegation for TLS

Alber, L. (Speaker), More, S. J. (Contributor), Sebastian Ramacher (Contributor)

Activity: Talk or presentationTalk at conference or symposiumScience to science

Description

On today's Internet, combining the end-to-end security of TLS with Content Delivery Networks (CDNs) while ensuring the authenticity of connections results in a challenging delegation problem. When CDN servers provide content, they have to authenticate themselves as the origin server to establish a valid end-to-end TLS connection with the client. In standard TLS, the latter requires access to the secret key of the server. To curb this problem, multiple workarounds exist to realize a delegation of the authentication.

In this paper, we present a solution that renders key sharing unnecessary and reduces the need for workarounds. By adapting identity-based signatures to this setting, our solution offers short-lived delegations. Additionally, by enabling forward-security, existing delegations remain valid even if the server's secret key leaks. We provide an implementation of the scheme and discuss integration into a TLS stack. In our evaluation, we show that an efficient implementation incurs less overhead than a typical network round trip. Thereby, we propose an alternative approach to current delegation practices on the web.
Period9 Nov 2020
Event titleThe ACM Cloud Computing Security Workshop: in conjunction with the ACM Conference on Computer and Communications Security (CCS)
Event typeWorkshop
LocationVirtuell, United States
Degree of RecognitionInternational