[1]

Webstore Hosting and Updating - Google Chrome (2018-03-19 22:10:39 +09:00) https://developer.chrome.com/extensions/hosting

All extensions are distributed to users as a special ZIP file with a .crx suffix. Extensions hosted in the Chrome Web Store are uploaded through the Developer Dashboard as .zip files. The publishing process automatically converts the .zip into a .crx file.

[2] CRX File, 2024-06-04T13:30:57.000Z https://chromium.googlesource.com/chromium/src/+/lkgr/components/crx_file/README.md

[3] components/crx_file/crx3.proto - chromium/src.git - Git at Google, 2024-06-04T13:31:15.000Z https://chromium.googlesource.com/chromium/src.git/+/62.0.3202.58/components/crx_file/crx3.proto

[4] ZIPファイルの署名