We would like to share a Tips from huffingtonpost.com on how you can secure your Twitter account.
Visit your account settings page. Go to Security and Privacy Select "Require a verification code when I sign in." Click on the link to "add a phone" and follow the prompts. After you enroll in login verification, you'll be asked to enter a six-digit code that Twitter will send to your phone via SMS each time you sign in to www.twitter.com.