"As others have already noted, HTTPS has nothing to do with torrents.
But in uTorrent you can enable encryption for outgoing connections, and optionally accept only encrypted incoming connections from others. Just download latest uTorrent version, go to Preferences > BitTorrent and in Protocol Enctiption select appropriate settings:
Disabled: Does not encrypt outgoing connections, but will accept encrypted incoming connections. Enabled: Attempts to encrypt outgoing connections, but will fall back to an unencrypted mode if the connection fails. Force: Attempts to encrypt outgoing connections, and will NOT fall back to an unencrypted mode if the connection fails. Allow legacy incoming connections enables or disables incoming legacy (non-encrypted) connections.
ED: @Am1rr3zA: ...what's best setting...
Well, it depends :) If it is just 'enabled', then some of the connections may still be unencrypted. If it is 'forced', then some of the outgoing connections may be dropped, and upload speed will be somewhat lower. If 'allow legacy incoming connections' is enabled, then again some of the connections won't be encrypted 'cause the other side does not support it. If it is disabled, then some of the incoming connections will be dropped, and download speed will be lower.
You have to decide for yourself what is more important. It's a trade off between speed and security. Personally for me 'enabled' with 'legacy connections' allowed is quite enough to satisfy my level of paranoia :]"
"You better use encrypted tunnel on your PC before starting torrent clients or browsing, this way all your traffic will be encrypted and secured. There are good services that provide all in one solutions to be protected in web, torrenting, unblock Skype etc. They are listed here : http://blog.pirateray.com/post/35136605543/pirateray-and-vpn-review"