You misunderstand @prakashghai. steemit is NOT steem blockchain. steemit.com is just an app on the chain and a pretty crappy one at that. Better ones include dlive, dtube, dsound, zappl, steempeak, and on and on and on.

In fact, steemit.com is probably the LEAST secure of them. But they all work the same way, and your keys are not sent over the wire on known and trusted apps, which you can tell are such, exactly BECAUSE they use steemconnect, the vetted, correct way to use such dapps.