Yeah, it's only four letters, but it is what it is.

Satoshi  Suggested by MattieIsHere 

It's their custom font - called Satoshi.
These guys made it: https://www.skinn.be/en/work/cdenv-rebranding
But be aware that the logo uses the modified version of the font

Edit: It's also on their website too (just extract the font files and voila): https://www.cdenv.be/