Sharing Is Caring: Hurdles and Prospects of Open, Crowd-Sourced Cyber Threat Intelligence

Cyber threat intelligence (CTI) is widely recognized as an important area in cybersecurity but it remains an area showing silos and reserved for large organizations. For an area whose strength is in open and responsive sharing, we see that the generation of feeds has a small scale, is secretive, and is nearly always from specialized businesses that have a commercial interest in not publicly sharing insights at a speed where it could be effective in raising preparedness or stopping an attack. This article has three purposes. First, we extensively review the state and challenges of open, crowd-sourced CTI, with a focus on the perceived barriers. Second, having identified that confidentiality (in multiple forms) is a key barrier, we perform a confidentiality threat analysis of existing sharing architectures and standards, including reviewing circa one million of real-world feeds between 2014 and 2022 from the popular open platform MISP toward quantifying the inherent risks. Our goal is to build the case that, either by redesigning sharing architectures or simply performing simple sanitization of shared information, the confidentiality argument is not as strong as one may have presumed. Third, after identifying key requirements for open crowd-based sharing of CTI, we propose a reference (meta-) architecture.