I just noticed that most of the ssh pubkeys in my authorized_keys end on == or =
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA9ZUwxXn2HZAAUswoaV8t2sQPvolVWDI053f0giNN154Zyi9FtWJKvyLHXoxW4IzFxgx+m6EYqXG/XCtfamLhwvGZv9FXkgQKeF6HJv/rjyKRBHPRyX0vV4S9uQU+xQV7f0Ock3urSzbUyoCgngA8Ax6AkYGmMTLLjx1HOBO/TJ477aysWt4IAg1gviT50I4xOYiHT4vC67czoDTnPl0UfKQJaM0+6WrneK7FJbd/8CAX7P7IxOhj1OxVbnEoh9FvecLbSDdOx/LF+kJcav/LThuoG7NR+Y+rS9lNkta3/KPi3IBMPum+bZpXJF7fkHl9Kx/iOMitT7KjNW/mty74xw== foo@bar
However today I saw a pubkey without an equal sign at the end. Also I noticed that the only place where an = ever occurs in a pubkey is at the end and never anywhere else.
Now I'm just curious as to what is the meaning of zero, one or two equal signs at the end of a pub key?