That is a tough one, I really want to like it. there are possibilities F = financial, file, etc. But, I'm not sure it is a sell it's self type name. And, cant put my finger on it but "fen" feels strange to me - and cant avoid reading/saying it. But that is purely subjective and what stuck in my head.
It may be worth getting into one of the big brandable sites and see if they accept and value it. Because the crypto market is slumping (atm) its not really a not an "easy sell", but encrypt is a strong keyword and generally brandable .
Play the encrypt angle as the brand and f is what the buyer wants it to be.
Wont be much of a sale to an investor - but could be x,xxx to the right end user.
as always all, please take my opinion with a grain of salt.
Thanks,
Brian