It is proven! I am jwmasek on Keybase: https://keybase.io/jwmasek/sigchain#b827e4a976c53f03418db21786a37de9b2bbb12083b4cc7c92726394c671e6e40f
the mastodon instance at cybre.space is retired see the end-of-life plan for details: https://cybre.space/~chr/cybre-space-eol
