There are a number of ways you can maintain your browser’s speed and security:

One of the most important aspects of internet security is a good password. It’s the weakest link in any online security or encryption for the following reason: it’s heavily dependent on the user. Most online security uses randomization to keep data secure, and one of the most common techniques for illegally gaining access to your accounts is called social engineering: basically, they gather as much data as possible about you and use that data to guess your passwords.

The best way to combat that is to use a randomized, strong password consisting of a mix of letters, numbers, and symbols. It can’t be any sort of recognizable word, because that sort of thing can be brute-forced (a process where thousands of logins are attempted, with minorly-varying passwords, in order to gain access by getting just the one right). It’s best if the password isn’t a recognizable pattern, to prevent that sort of attack.

An excellent source for generating a strong password is:

Strong Password Generator