Source URL: https://dadrian.io/blog/posts/sct-not-after/
Source: Hacker News
Title: How to distrust a CA without any certificate errors
Feedly Summary: Comments
AI Summary and Description: Yes
**Summary:** The text discusses the concept of “distrust” in the context of certificate authorities (CAs) that issue HTTPS certificates, emphasizing changes in the management of certificate trustworthiness due to compliance failures and the introduction of Certificate Transparency (CT). This evolution enhances user security and addresses key compromise issues by allowing for forward-looking distrust mechanisms.
**Detailed Description:**
The text provides a comprehensive examination of the distrust of certification authorities (CAs) in the realm of Web Public Key Infrastructure (PKI). Here are the key points elaborated:
– **Definition of Distrust:**
– Distrust occurs when a CA is removed from a trusted root store, rendering its certificates invalid.
– Often triggered by security reasons, compliance issues, or diminished trust in the CA itself.
– **Historical Context:**
– Past distrust events were complex, especially for larger CAs, impacting user experience and requiring prolonged timelines.
– **Impact of Certificate Transparency (CT):**
– New requirements for certificates to be logged in public CT logs have shifted the nature of distrust events.
– Maliciously issued certificates now need to be logged, making unauthorized activities publicly auditable and less viable.
– **Compliance and the Baseline Requirements (BRs):**
– Distrust events have transitioned from key compromises to repeated non-compliance with the BRs, which define CA operational standards.
– **Certificate Lifetimes:**
– Current regulations limit certificate lifetimes to a maximum of 398 days, with proposals to shorten this to 47 days.
– This strategy enhances security by ensuring that only recent certificates are valid, making older certificates less susceptible to manipulation.
– **Forward-Looking Distrust Mechanism:**
– Modern distrusts can focus on future certificates only, allowing existing valid certificates to remain operational while discouraging further trust in a malfunctioning CA.
– The SCTNotAfter mechanism is introduced to enforce this process, ensuring that existing certificates can still function while preventing new problematic certificates from being issued.
– **Case Studies of Distrust Events:**
– The implementation of SCTNotAfter was used effectively during distrust events involving GLOBALTRUST and Entrust, avoiding widespread user-facing errors.
– **Future of Web PKI:**
– The overall narrative emphasizes the need for continuous improvement in CA practices and browser security to minimize distrust instances.
**Implications for Security Professionals:**
– Understanding the evolution of trust mechanisms among CAs is crucial for compliance and security frameworks.
– The introduction of CT and shorter certificate lifetimes urges organizations to adapt to faster transitions and stay compliant with the latest requirements.
– Security professionals should remain vigilant about their certificate authorities’ reliability and readiness to respond to compliance impacts, ensuring a robust Web PKI system that benefits end users.