As stated by @lehnberg, I really like the idea of not having any “official” logo but maybe using the currency symbol of Grin as a logo.
Here’s my submission.
The Patronus.
There is a subtle white aura around the currency symbol which embodies the HP roots of Grin and the MW protocol.
As suggested by @0xb100d, I used the courrier font which is a font almost every computers in the world have.
