Posted by Ryan Hurst, Security and Privacy Engineering In support of our work to implement HTTPS across all of our products (https://www.google.com/transparencyreport/https/) we have been operating our own subordinate Certificate Authority (GIAG2), issued by a third-party. This has been a key element enabling us to more rapidly handle the SSL/TLS certificate needs of Google products. As we look forward to the evolution of both the web and our own products it is clear HTTPS will continue to be a foundational technology. This is why we have made the decision to expand our current Certificate Authority efforts to include the operation of our own Root Certificate Authority. To this end, we have established Google Trust Services (https://pki.goog/), the entity we will rely on to operate these Certificate Authorities on behalf of Google and Alphabet. The process of embedding Root Certificates into products and waiting for the associated versions of those products to be broadly deployed can take time. For this reason we have also purchased two existing Root Certificate Authorities, GlobalSign R2 and R4. These Root Certificates will enable us to begin independent certificate issuance sooner rather than later. We intend to continue the operation of our existing GIAG2 subordinate Certificate Authority. This change will enable us to begin the process of migrating to our new, independent infrastructure. Google Trust Services now operates the following Root Certificates: Public Key Fingerprint (SHA1) Valid Until GTS Root R1 RSA 4096, SHA-384 e1:c9:50:e6:ef:22:f8:4c:56:45:72:8b:92:20:60:d7:d5:a7:a3:e8 Jun 22, 2036 GTS Root R2 RSA 4096, SHA-384 d2:73:96:2a:2a:5e:39:9f:73:3f:e1:c7:1e:64:3f:03:38:34:fc:4d Jun 22, 2036 GTS Root R3 ECC 384, SHA-384 30:d4:24:6f:07:ff:db:91:89:8a:0b:e9:49:66:11:eb:8c:5e:46:e5 Jun 22, 2036 GTS Root R4 ECC 384, SHA-384 2a:1d:60:27:d9:4a:b1:0a:1c:4d:91:5c:cd:33:a0:cb:3e:2d:54:cb Jun 22, 2036 GS Root R2 RSA 2048, SHA-1 75:e0:ab:b6:13:85:12:27:1c:04:f8:5f:dd:de:38:e4:b7:24:2e:fe Dec 15, 2021 GS Root R4 ECC 256, SHA-256 69:69:56:2e:40:80:f4:24:a1:e7:19:9f:14:ba:f3:ee:58:ab:6a:bb Jan 19, 2038 Due to timing issues involved in establishing an independently trusted Root Certificate Authority, we have also secured the option to cross sign our CAs using: Public Key Fingerprint (SHA1) Valid Until GS Root R3 RSA 2048, SHA-256 d6:9b:56:11:48:f0:1c:77:c5:45:78:c1:09:26:df:5b:85:69:76:ad Mar 18, 2029 GeoTrust RSA 2048, SHA-1 de:28:f4:a4:ff:e5:b9:2f:a3:c5:03:d1:a3:49:a7:f9:96:2a:82:12 May 21, 2022 If you are building products that intend to connect to a Google property moving forward you need to at minimum include the above Root Certificates. With that said even though we now operate our own roots, we may still choose to operate subordinate CAs under third-party operated roots. For this reason if you are developing code intended to connect to a Google property, we still recommend you include a wide set of trustworthy roots. Google maintains a sample PEM file at (https://pki.goog/roots.pem) which is periodically updated to include the Google Trust Services owned and operated roots as well as other roots that may be necessary now, or in the future to communicate with and use Google Products and Services. 