what if they have my sec key?

[Ramon Loureiro]

Hi!

I'm using different PCs at work for sending email (and other things, of 
course...)
They are shared with 3 more users.

Is it possible for these users to hack my secret key?
If they have got it, can they use some kind of brute force system to 
guess my pass phrase?

What will be the best option in this scenario?
Having the secret key on my USB drive?
?

Thanks!