I am a new Ubuntu user (using it since last 1 month). When I was with windows there were all these Internet Security Suites that protected the PC.
With Ubuntu there aren't any. I wanted to know if I download torrents, will someone be able to hack into my system?
Since all the peers can see my IP address, will they be able to break into my system?
I know the question sounds n00bish, but then I am a n00b.
PS: Ubuntu and Transmission are all up to date in my system.
Nothing is hack-proof but you're safer than the average Windows PC.
I assume you are connecting via a router. In that case the router will probably block everything incoming except stuff on the bittorrent ports so unless they have an exploit in transmission (which would be specific to transmission) you are probably safe.
BTW consumer grade windows firewalls won't help you either in this situation. Since you are actually requesting bittorrent traffic, the firewalls aren't going to block it. Some of the smarter windows AV might detect and try to block them after they get in, or might flag some suspicious traffic patterns, but that's a different story ... :-)