Infrastructure report cardTop 1K site

claude.ai

88 out of 10016 passed4 to improve

Checked yesterday· Grading…

HTTPS & TLSA

Certificate, protocol, redirect, HSTS88

DNSB

Name servers, DNSSEC, CAA, registration79

EmailA

SPF, DMARC, MTA-STS, DKIM93

Web & networkA⁺

Security headers, IPv6, RPKI100

DependenciesB

How much hangs on one company80

HTTPS & TLS

88/100A

HSTS0/4
No HSTS: a visitor's first request can be downgraded to plain HTTP.
HTTPS certificateLet's Encrypt10/10
HTTPS with a valid certificate from Let's Encrypt.
Certificate expiry564/4
The certificate is valid for another 56 days.
TLS versionTLS 1.34/4
Negotiates TLS 1.3, the current protocol: faster handshakes, forward secrecy always.
Old protocols3/3
Refuses the retired TLS 1.0 and 1.1.
Key strengthECDSA P-2562/2
A strong key: ECDSA P-256.
HTTP → HTTPS3013/3
http:// redirects straight to https://.
HTTP/2 and HTTP/3HTTP/32/2
HTTP/2 and HTTP/3.

DNS

79/100B

DNSSEC0/3
Not signed with DNSSEC: a forged DNS answer for the domain cannot be told from the real one.
Name servers24/4
2 name servers for the domain.
Name servers answer2/25/5
Every name server answers for the domain, with the same version of the zone.
CAA recordsawstrust.com, comodoca.com, digicert.com, letsencrypt.org, pki.goog, ssl.com, amazon.com, amazonaws.com, amazontrust.com2/2
CAA records name the authorities allowed to issue its certificates.

Email

93/100A

Null MX0/1
No MX records, and no null MX to say the domain takes no mail.
SPF-all5/5
SPF lists the servers allowed to send its mail and rejects the rest (-all).
DMARCreject7/7
DMARC tells receivers to reject mail that fakes the domain (p=reject).
DKIMgoogle2/2
A DKIM key is published (selector google), so its mail can be signed.

Web & network

100/100A⁺

Security headers
The website answered 403 to the check (bot protection, most likely), so its headers are not graded.
IPv64/4
claude.ai is reachable over IPv6 as well as IPv4.
RPKIvalid4/4
The route to the website is RPKI-valid: networks can reject hijacked announcements of it.

Dependencies

80/100B

DNS providersCloudflare3/5
All DNS is with one provider (Cloudflare): an outage there takes the domain offline, as Dyn's did in 2016.
One company for everything5/5
The website, DNS and email do not all hang on one company.

Who runs it

Website: ANTHROPIC
DNS: Cloudflare
Email: —

Routes

160.79.104.0/23AS399358RPKI valid
2607:6bc0::/48AS399358RPKI valid

Name servers

isla.ns.cloudflare.comCloudflareAS13335
randy.ns.cloudflare.comCloudflareAS13335

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What is graded

HTTPS & TLS · 25%

A valid certificate (an invalid one means F), its expiry against its lifetime, TLS 1.3, no TLS 1.0/1.1 (else at most B), http:// sent straight to https://, HSTS, HTTP/2.

DNS · 20%

At least two name servers that all answer and agree, DNSSEC, CAA records, and a registration that is not about to expire.

Email · 20%

SPF, a DMARC policy that rejects forgeries (none means at most B), MTA-STS and TLS reporting for domains that take mail, DKIM at common selectors.

Web & network · 20%

Content Security Policy, nosniff, framing protection, Referrer- and Permissions-Policy, IPv6, and an RPKI-valid route (invalid means at most C).

Dependencies · 15%

DNS from more than one provider, and the website, DNS and email not all with one company.

A+ 95–100 · A 85–94 · B 75–84 · C 65–74 · D 50–64 · F below 50