{"id":10,"date":"2026-04-05T19:58:20","date_gmt":"2026-04-05T19:58:20","guid":{"rendered":"https:\/\/open-ca.eu\/?page_id=10"},"modified":"2026-04-05T20:21:49","modified_gmt":"2026-04-05T20:21:49","slug":"frontpage","status":"publish","type":"page","link":"https:\/\/open-ca.eu\/","title":{"rendered":"open-ca.eu"},"content":{"rendered":"\n
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What we built<\/p>\n

Real applications. Real trust.<\/h2>\n

Digital trust is invisible infrastructure \u2014 until you need it. open-ca.eu makes it tangible: free tools anyone can use today, backed by open-source cryptographic infrastructure built to last 25 years.<\/p>\n<\/div><\/div>\n\n\n\n

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Start here<\/p>\n

What can you do right now?<\/h2>\n\n
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open-smime.eu<\/p>\n

Get your S\/MIME certificate<\/h3>\n

Cryptographically prove who you are when you send email. Works in Outlook, Apple Mail, Thunderbird. Free, no account required for the basic tier.<\/p>\nCreate certificate →<\/a>\n<\/div>\n\n

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open-email.eu<\/p>\n

The world’s first email with automatic send proof<\/h3>\n

Every email you send gets a cryptographic timestamp and hash. Proof of exactly what you sent, to whom, and when \u2014 better than a registered letter. Better than fax.<\/p>\nSend provable email →<\/a>\n<\/div>\n\n

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open-tsa.eu<\/p>\n

Timestamp any document<\/h3>\n

RFC 3161 cryptographic proof that your document, contract, or code existed at a specific point in time. Free. No account. Legally relevant in the EU.<\/p>\nTimestamp now →<\/a>\n<\/div>\n\n

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euforge.eu<\/p>\n

Host your code in Europe<\/h3>\n

Git hosting with built-in OIDC authentication and automatic TSA commit signing. Every commit cryptographically timestamped. No US cloud, no Cloud Act.<\/p>\nExplore euforge →<\/a>\n<\/div>\n\n

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open-mta.eu<\/p>\n

European mail infrastructure<\/h3>\n

The open mail transfer backbone behind open-email.eu. Self-hostable, auditable, GDPR-compliant by architecture. For organisations that need full control.<\/p>\nLearn more →<\/a>\n<\/div>\n\n

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open-ca.eu<\/p>\n

The root of trust<\/h3>\n

The certificate authority behind everything. 4-tier hierarchy, air-gapped root key, 25-year validity. Issues intermediate CAs for every open-ca.eu project.<\/p>\nCA documentation →<\/a>\n<\/div>\n\n<\/div>\n<\/div><\/div>\n\n\n\n

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Architecture<\/p>\n

One root. Many services.<\/h2>\n

All open-ca.eu projects share a common cryptographic root. The hierarchy is designed for long-term stability \u2014 the root key never touches an online system.<\/p>\n\n

\nopen-ca.eu Root CA                     (2026-2051, 25 years, air-gapped)\n    +-- open-tsa.eu TSA Root CA        (2026-2041, 15 years)\n    |       +-- TSA Intermediate CA    (2026-2036, 10 years)\n    |               +-- TSA Signing    (2 years, rotated)\n    +-- open-smime.eu S\/MIME CA        (roadmap)\n    +-- open-email.eu MTA CA           (roadmap)\n    +-- euforge.eu Code Signing CA     (roadmap)\n<\/pre>\n<\/div><\/div>\n\n\n\n
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Principles<\/p>\n
Why open-ca.eu?<\/h2>\n\n
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European by Design<\/h3>\n
All servers in Germany. No US cloud, no Cloud Act exposure. GDPR compliant by architecture \u2014 not by policy or promise.<\/p>\n<\/div>\n\n
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Truly Open Source<\/h3>\n
MIT licensed. Every line of code is public. Self-host the entire stack if you want full control. No vendor lock-in, ever.<\/p>\n<\/div>\n\n
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Free Forever<\/h3>\n
Core services are and will remain free. Supported by NLnet, Sovereign Tech Fund, and the community \u2014 not by selling user data.<\/p>\n<\/div>\n\n<\/div>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"
What we built Real applications. Real trust. Digital trust is invisible infrastructure \u2014 until you need it. open-ca.eu makes it tangible: free tools anyone can use today, backed by open-source cryptographic infrastructure built to last 25 years. Start here What can you do right now? open-smime.eu Get your S\/MIME certificate Cryptographically prove who you are […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"front-page.php","meta":{"footnotes":""},"class_list":["post-10","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/open-ca.eu\/index.php?rest_route=\/wp\/v2\/pages\/10","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/open-ca.eu\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/open-ca.eu\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/open-ca.eu\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/open-ca.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10"}],"version-history":[{"count":3,"href":"https:\/\/open-ca.eu\/index.php?rest_route=\/wp\/v2\/pages\/10\/revisions"}],"predecessor-version":[{"id":13,"href":"https:\/\/open-ca.eu\/index.php?rest_route=\/wp\/v2\/pages\/10\/revisions\/13"}],"wp:attachment":[{"href":"https:\/\/open-ca.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}