What Is HTTPS and Why Is It Still Essential for Cybersecurity in 2025?

**Executive summary:** This advisory explains why HTTPS/TLS remains essential for confidentiality, integrity, and authenticity of web and API traffic, outlines common misconfigurations and threats (expired certificates, weak ciphers, TLS downgrade and certificate spoofing, SSL stripping), highlights the supply-chain risk when vendors mismanage HTTPS, and provides 2025-era best practices—such as adopting TLS 1.3, disabling older protocols, enabling HSTS, automating certificate monitoring, and using CSPs—while recommending continuous monitoring and third-party assessment tools like SecurityScorecard SCDR to reduce exposure.