Meeting the FedRAMP High Baseline TLS configuration requirements is not optional—it is mandatory for systems handling the most sensitive government data. These requirements are strict. They define exactly which ciphers, protocols, and key lengths are acceptable. Deviate, and you fail certification.
Protocols
The FedRAMP High Baseline enforces the use of TLS 1.2 or higher. TLS 1.3 is preferred for its improved security and reduced handshake overhead. All earlier versions—TLS 1.0, 1.1—must be disabled at the server level.
Cipher Suites
Weak algorithms are forbidden. RC4, 3DES, and any cipher with less than 128-bit key strength cannot be used. FedRAMP aligns with NIST guidelines, recommending AES-GCM with 256-bit keys, paired with elliptic curve Diffie-Hellman (ECDHE) for forward secrecy. For TLS 1.2, suites like TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 meet the baseline. For TLS 1.3, the allowed set is smaller but stronger, with defaults like TLS_AES_256_GCM_SHA384.
Key Management
The High Baseline requires RSA keys at least 2048 bits or ECDSA using P-256 or stronger curves. Keys must be rotated regularly and stored in FIPS 140-2 validated modules. Self-signed certificates are not acceptable in production—only CA-issued certificates that meet the trust chain requirements.