Is it possible to use SATA HDD as Network Storage?

here is scenario,

I have 1TB internal SATA HDD, which is connected to a Desktop. If I want to access the files in this HDD from a Laptop, I have to switch on this Desktop and should either use ssh (sftp) or Windows Share. I find this approach as tedious, wast of electricity and also slow approach, as Desktop's boot up and login time.

I am wondering, that, is there any alternative solution where I can use HDD as Network Storage, with following additional requirement.

1. Easy access to file as if HDD is connected to Computer directly (No Much Setup)
2. Can be easily accessed from Windows, Linux and Mac.
3. Implements Security Features.
4. Using Storage (HDD) over Internet. (optional)
5. Provision to add additional HDDs

I might have misunderstood your question, but a NAS would fill all your requirements. I'm using the ReadyNAS Duo myself. It goes at around 180$ and has slots for 2xHDDs