Is Capital One quantum-safe?
Partly. 10 of 12 public servers under capitalone.com use post-quantum key exchange, the protection against traffic recorded today being decrypted once a large quantum computer exists. Grade B. Scanned October 18, 2026.
2 other servers without post-quantum key exchange
- mail.capitalone.com
- metrics.capitalone.com
10 servers already protected
- api.capitalone.com
- beta-creditwise.capitalone.com
- capitalone.com
- creditwise.capitalone.com
- developer.capitalone.com
- go.capitalone.com
- m.capitalone.com
- mobile.capitalone.com
- preprod-creditwise.capitalone.com
- www.capitalone.com
What this means
NIST has scheduled the key exchange most servers still use for retirement: deprecated after 2030, disallowed after 2035 (NIST IR 8547). Traffic recorded today can be decrypted once a large quantum computer exists. A server that offers hybrid ML-KEM key exchange closes that today; a server that does not is still open to harvest now, decrypt later.
Hostnames come from public certificate logs plus common service names, kept where the name resolves to a public address, and each is tested from the outside with post-quantum-only TLS 1.3 handshakes. A hostname shows what a server is called, not what traffic it carries; internal systems are out of scope. Method.
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<a href="https://latticescan.com/readiness/capitalone.com"><img src="https://latticescan.com/badge/readiness/capitalone.com" alt="quantum readiness"></a>