[Gateway] Post-quantum TLS decryption (#19478)

Author: maxvp

src/content/docs/cloudflare-one/policies/gateway/http-policies/tls-decryption.mdx

@@ -95,6 +95,10 @@ Websites that adhere to [ESNI or ECH standards](https://blog.cloudflare.com/encr
 
 You can still apply all [network policy filters](/cloudflare-one/policies/gateway/network-policies/#selectors) except for SNI and SNI Domain. To restrict ESNI and ECH traffic, an option is to filter out all port `80` and `443` traffic that does not include an SNI header.
 
+## Post-quantum support
+
+Gateway supports post-quantum cryptography using a hybrid key exchange with X25519 and MLKEM768 over TLS 1.3. Once the key exchange is complete, Gateway uses AES-128-GCM to encrypt traffic.
+
 ## FIPS compliance
 
 By default, TLS decryption can use both TLS version 1.2 and 1.3. However, some environments such as FedRAMP may require cipher suites and TLS versions compliant with FIPS 140-2. FIPS compliance currently requires TLS version 1.2.