Evidence of log integrity in policy-based security monitoring

Monitoring systems are commonly used by many organizations to collect information about their system and network operations. Typically, SNMP, IDS, or software agents generate log data and store them in a centralized monitoring system for analysis. However, malicious employees, attackers, or even organizations themselves can modify such data to hide malicious activities or to avoid expensive non-compliance fines. This paper proposes a cloud-based framework for verifying the trustworthiness of the logs based on a small amount of evidence data. A simple Cloud Security Monitoring (CSM) API, made available on the cloud services, allows organizations operating on the cloud to collect additional 'evidence' about their systems. Such evidence is used to verify system compliance against the policies set by security managers or regulatory authorities. We present a strategy for randomly auditing and verifying resource compliance, and propose an architecture that allows the organizations to prove compliance to an external auditing agency.