GitHub's Chief Security Officer, Mike Hanley, emphasizes the importance of supply chain security, which has gained significant attention due to incidents like the SolarWinds attack. Hanley suggests three key strategies to enhance security: understanding and securing build pipelines, implementing two-factor authentication (2FA) for all code contributors, and ensuring artifact provenance through tools like Sigstore. These measures aim to protect software applications and open-source ecosystems from vulnerabilities and attacks. Hanley points out that despite the focus on advanced threats, fundamental practices like 2FA can significantly reduce risks such as phishing. He advocates for a collective effort to maintain the integrity of open-source code and dependencies, urging organizations to assess their security controls, verify third-party dependencies, and review integrations to meet security standards.