USB flash security software between mac and PC

Hi

I have recently started work at a new firm who are all very fond of macs. My problem is that I take a lot of work home on a flash drive to my home PC. Up until now I was using the swittbit secure lock software. But my understanding is that .exe files dont work on mac.

Is there a programme somewhere that can secure my usb flash drive with a password or something of the like and still be accessible on both PC and Macs?

Can someone please help me, I carry a lot of confidential information around. I am very careful not to loose it, but accidents happen.

Thanks