# Atos TrustedRoot Root CA RSA TLS 2021 root certificate (Atos)

> Atos TrustedRoot Root CA RSA TLS 2021 is a root CA certificate operated by Atos (RSA 4096, valid until 2041-04-17, SHA-256 81A9088E). As of the latest CCADB data it is trusted for TLS server authentication by 4 of 4 major root stores: Chrome, Mozilla, Apple, Microsoft.

Source: https://ssl.sh/roots/atos-trustedroot-root-ca-rsa-tls-2021/
Last updated: 2026-11-10

Atos TrustedRoot Root CA RSA TLS 2021 is a root CA certificate operated by Atos (RSA 4096, valid until 2041-04-17, SHA-256 81A9088E). As of the latest CCADB data it is trusted for TLS server authentication by 4 of 4 major root stores: Chrome, Mozilla, Apple, Microsoft.

| Field | Value |
|---|---|
| CA owner | Atos |
| Subject | C=DE,O=Atos,CN=Atos TrustedRoot Root CA RSA TLS 2021 |
| SHA-256 | 81A9088EA59FB364C548A6F85559099B6F0405EFBF18E5324EC9F457BA00112F |
| SPKI SHA-256 | F7CA77A610E3D42447240692DBD57CFD13CF042ACD2062E6A62B87B9ED81C1A7 |
| Valid from | 2021-04-22 |
| Expires | 2041-04-17 |
| Key | RSA 4096 |
| Signature algorithm | sha384WithRSAEncryption |
| Serial number | 53D5CFE619930BFB2B0512D8C22AA2A4 |
| SHA-1 (Windows thumbprint) | 18523B0D0637E4D63ADF23E498FB5B16FB867448 |

## Root store status

| Root store | Status | Trusted for TLS | Distrust for TLS after | Details |
|---|---|---|---|---|
| Chrome | Included | Yes | - | - |
| Mozilla | Included | Yes | - | Trust bits: Websites; EV policy OIDs: not EV-enabled; First included in: NSS 3.92 / Firefox 117; Inclusion bug: #1782092 |
| Apple | Included | Yes | - | Trust bits: serverAuth |
| Microsoft | Included | Yes | - | Trusted EKUs: Server Authentication, Client Authentication |

The CCADB lists no EV policy OID for Atos TrustedRoot Root CA RSA TLS 2021.

## Intermediate CAs issued by this root

The CCADB lists 1 intermediate CA certificates signed directly by Atos TrustedRoot Root CA RSA TLS 2021: 1 currently valid, 0 expired and 0 revoked (revoked includes those whose parent was revoked).

| Intermediate | Operated by | Expires | Status | SHA-256 |
|---|---|---|---|---|
| Atos TrustedRoot Server CA RSA 2022 | Atos | 2032-07-09 | Valid | 843103FDC2E04B5115C78CC7C47D802ABEF427216E5BBD0946D105751868C3B5 |

## Cross-signed versions

No certificate in the CCADB has the same subject and public key as Atos TrustedRoot Root CA RSA TLS 2021 with a different issuer, so a client has to carry Atos TrustedRoot Root CA RSA TLS 2021 itself in its root store to trust it.


## What happens when it expires

Atos TrustedRoot Root CA RSA TLS 2021 is valid until 2041-04-17, about 14.4 years after this data snapshot (2026-11-10). From that day, browsers and operating systems that check trust-anchor expiry stop accepting chains that end at this root, so any certificate that can only chain to it fails validation. Android is a known exception: it does not enforce the expiry date of trust anchors.

## FAQ

**Is Atos TrustedRoot Root CA RSA TLS 2021 trusted by Chrome, Firefox, Safari and Windows?**

Yes. As of 2026-11-10, Chrome, Mozilla (Firefox), Apple (Safari) and Microsoft (Windows) all trust it for TLS server authentication.

**When does Atos TrustedRoot Root CA RSA TLS 2021 expire?**

On 2041-04-17, about 14.4 years after the 2026-11-10 data snapshot.

**How many intermediate certificates has Atos TrustedRoot Root CA RSA TLS 2021 issued?**

The CCADB lists 1: 1 valid, 0 expired and 0 revoked. The newest valid one is Atos TrustedRoot Server CA RSA 2022, valid until 2032-07-09.

**Is Atos TrustedRoot Root CA RSA TLS 2021 cross-signed?**

No. The CCADB has no certificate with the same subject and public key signed by another CA.

Sources: CCADB TLS Server Authentication report, All Included Root Certificate Trust Bit Settings, All Certificate Information (V5), the per-store TLS reports and Mozilla's Included CA Certificate Report (ccadb.org/resources).