Skip to content
Vol. 1 · Ed. 2026
CyberGlossary
Entry № 841

Oblivious HTTP (OHTTP)

Qu'est-ce que Oblivious HTTP (OHTTP) ?

Oblivious HTTP (OHTTP)An IETF-standardized HTTP-over-HPKE relay protocol (RFC 9458) that decouples client identity from request content by splitting trust between a relay (sees IP, not content) and a gateway (sees content, not IP).


Oblivious HTTP (OHTTP), specified in RFC 9458 (2024), is a privacy-preserving relay protocol for HTTP requests. The client encrypts the inner request with HPKE (Hybrid Public-Key Encryption, RFC 9180) using the gateway server's public key, then sends the encrypted payload over a normal TLS connection to a separate relay server. The relay decrypts only the outer envelope, sees the client's IP but not the request, and forwards the encrypted payload to the gateway; the gateway decrypts and processes the request, sees the request and response, but never sees the client's IP. This split-trust model means no single party knows both 'who' and 'what'. Use cases include Apple Private Relay-style web access, DNS over Oblivious HTTP, telemetry pipelines (Mozilla, Cloudflare), 'private prefetch proxy' deployments, and certificate-revocation lookups. The companion 'oblivious DoH' (ODoH, RFC 9230) is an OHTTP-style relay specific to DNS resolution. OHTTP requires the client to trust that the relay and gateway are run by non-colluding parties, which is the central operational assumption.

Exemples

  1. 01

    An operating system fetches certificate-revocation status via OHTTP so that revocation lookups cannot be tied to user IPs by either the CA or the network operator alone.

  2. 02

    A telemetry pipeline ships product-usage events through OHTTP, routing through a Fastly relay to a vendor's gateway, ensuring the vendor cannot tie events to client IPs.

Questions fréquentes

Qu'est-ce que Oblivious HTTP (OHTTP) ?

An IETF-standardized HTTP-over-HPKE relay protocol (RFC 9458) that decouples client identity from request content by splitting trust between a relay (sees IP, not content) and a gateway (sees content, not IP). Cette notion relève de la catégorie Sécurité réseau en cybersécurité.

Que signifie Oblivious HTTP (OHTTP) ?

An IETF-standardized HTTP-over-HPKE relay protocol (RFC 9458) that decouples client identity from request content by splitting trust between a relay (sees IP, not content) and a gateway (sees content, not IP).

Comment fonctionne Oblivious HTTP (OHTTP) ?

Oblivious HTTP (OHTTP), specified in RFC 9458 (2024), is a privacy-preserving relay protocol for HTTP requests. The client encrypts the inner request with HPKE (Hybrid Public-Key Encryption, RFC 9180) using the gateway server's public key, then sends the encrypted payload over a normal TLS connection to a separate relay server. The relay decrypts only the outer envelope, sees the client's IP but not the request, and forwards the encrypted payload to the gateway; the gateway decrypts and processes the request, sees the request and response, but never sees the client's IP. This split-trust model means no single party knows both 'who' and 'what'. Use cases include Apple Private Relay-style web access, DNS over Oblivious HTTP, telemetry pipelines (Mozilla, Cloudflare), 'private prefetch proxy' deployments, and certificate-revocation lookups. The companion 'oblivious DoH' (ODoH, RFC 9230) is an OHTTP-style relay specific to DNS resolution. OHTTP requires the client to trust that the relay and gateway are run by non-colluding parties, which is the central operational assumption.

Comment se défendre contre Oblivious HTTP (OHTTP) ?

Les défenses contre Oblivious HTTP (OHTTP) combinent habituellement des contrôles techniques et des pratiques opérationnelles, comme détaillé dans la définition ci-dessus.

Quels sont les autres noms de Oblivious HTTP (OHTTP) ?

Noms alternatifs courants : OHTTP, RFC 9458.

Termes liés