Qtonic Quantum Corp ranks first. Its public servers refuse the classical sessions an adversary can record today and decrypt once a quantum computer exists. None of the 50 largest security companies refuses them on a single server.
Qtonic Quantum Corp against the ten largest IT-security companies by market value.
Qtonic Quantum Corp against the five companies with the highest post-quantum coverage. They offer the hybrid group on nearly every server, and every one of those servers still accepts a classical session.
Ranked by the share of servers that refuse every classical handshake, then by the share that offer the post-quantum hybrid group. Select a company to inspect each of its servers.
| Server | Kind | Address | Hybrid only | X25519 only | P-256 only | TLS 1.2 | Result |
|---|---|---|---|---|---|---|---|
| Loading server records… | |||||||
This is the common industry measure. Companies behind Cloudflare, Akamai and Fastly score high because those networks offer the hybrid group by default. Several of the largest companies leave most servers classical only: Palo Alto Networks 30%, Fortinet 25%, F5 19%.
A recorded classical handshake can be decrypted once a large quantum computer exists. A server closes that path only if it refuses X25519, P-256 and TLS 1.2 alike. No server at any of the 50 companies does. Qtonic Quantum Corp refuses all three on 8 of its 9 servers.
Refusing classical has a cost: clients without the hybrid group cannot connect. curl built on OpenSSL 3.0.13 (the Ubuntu 24.04 default) fails against qtonicquantum.com. Companies that serve the general public accept classical sessions so older clients keep working. A 0% clean score reflects that choice, not neglect.
TLS 1.3 · X25519MLKEM768 only
TLS 1.3 · X25519 only
TLS 1.3 · P-256 only
TLS 1.2 · default suites
Mail servers are tested on port 25 after STARTTLS. A handshake counts as completed even if the certificate name does not match.
Each company's apex and www, the names from the first 2,400 labels of the SecLists subdomains-top1million-5000 list that resolve, names from certificate-transparency logs, and every published mail exchanger. The same method applies to every company, including Qtonic Quantum Corp.
A server that completes none of the four handshakes is left out of every percentage and shown as unmeasured in the explorer.
The first measurement of these servers was made earlier on 26 September. To check it, a separate probe written from scratch re-tested every server between 15:52 and 16:00 UTC from AWS us-west-2. The ranking on this page uses the replication.
2,860 of 2,889 servers measured in both runs got the same result (99.0%). Every conclusion held: no harvest-proof server at any of the 50 companies, and Qtonic Quantum Corp as the only company with harvest-proof servers.
27 of the 29 differences sit on one content-network address range (150.171.110.x). Re-tested three times, some of those servers switched between hybrid and classical between attempts. The replication also added qstrike.qtonicquantum.com, a name in Qtonic Quantum Corp's certificate logs that the first run missed. It is clean.
Qtonic Quantum Corp ranks first of 51. 88.9% of its public servers (8 of 9) offer the post-quantum hybrid group X25519MLKEM768 and refuse every classical handshake. No server at any of the 50 largest IT-security companies does both.
Each of the ten largest IT-security companies by market value has 0% harvest-proof servers. Their share of servers offering post-quantum key exchange ranges from 18.7% (F5) to 99.2% (Cloudflare). Qtonic Quantum Corp offers it on 100%.
A harvest-proof server refuses classical-only TLS sessions (X25519, P-256 and TLS 1.2) and accepts only the post-quantum hybrid group. Traffic recorded from it today cannot be decrypted later by a quantum computer, which defeats harvest-now, decrypt-later attacks.
On 2026-09-26, every public HTTPS and mail server found for each company (51 companies, 3,761 servers) was tested with four TLS handshakes. A second, independently written probe re-measured every server. It agreed on 99.0% of the servers that both runs measured.
Conflict of interest. Qtonic Quantum Corp publishes this page, designed the clean measure and ranks first on it. The hybrid column is included so the result can also be read on the common industry measure, where several companies tie Qtonic Quantum Corp at 100%.
Different estate sizes. Qtonic Quantum Corp has 9 measured servers. The 50 companies have between 5 and 163. A small estate is easier to keep uniform, so the percentages compare rates, not effort.
One day, public servers only. This is a snapshot of internet-facing TLS on 26 September 2026. It says nothing about internal systems, the products these companies sell, or their customers' deployments. Companies are the top 50 of the companiesmarketcap.com IT-security list as read that day.