The free service, called SiteKey, provides an extra level of authentication to enhance security. Customers pick one of thousands of images, write a brief phrase and select three challenge questions. The customer and the bank pass that information securely back and forth to confirm each other's identity.

Using SiteKey is like getting a safe deposit box that takes two keys to open. Before the customer and the bank agree to open the box together, they confirm each other's identity. Industry experts have recognized the bank as the first major financial services company to provide this added level of security.

Bank of America has the most online banking customers in the world, with 14.6 million subscribers and 7.2 million online bill payers. Bank of America customers make up more than 34 percent of all online bankers and more than 58 percent of online banking bill payers in the United States.

The most recent states to receive SiteKey were Connecticut, Massachusetts, Maine, New Hampshire, New Jersey, New York, Pennsylvania and Rhode Island. SiteKey is now available throughout the country, except in Washington and Idaho, where it will launch later this year. The free service is moving from an optional to a standard part of sign-in. Customers will be told about the change through onscreen messages in advance.

"We're the first major bank to offer this extra level of protection and we're making it a standard part of signing-in to help protect all of our Online Banking customers from fraud and identity theft," said Sanjay Gupta, e-Commerce executive. "Signing up for SiteKey only takes a few minutes, and it's easy to use because you don't need extra hardware or other equipment."

Also in December, the bank took an additional security step to help customers identify fraudulent Web sites by posting the Bank of America Toolbar, powered by EarthLink, on the home page for free. The toolbar provides an icon that changes colors as the consumer surfs the Internet, letting the person know with a red, yellow or green symbol whether they've landed on what could be a dangerous Web site. It also alerts consumers before they go to a Web page that is on a list of known phisher sites. The toolbar also includes a pop-up blocker tool, which prevents advertising windows from appearing in the consumer's main browser window.

SiteKey and the Bank of America Toolbar are part of an umbrella of security measures that includes a zero liability guarantee that protects customers from fraud losses, two-tiered authentication for funds transfers, and the capability for customers to stop receiving paper statements to reduce risks associated with sending sensitive information through the mail.

Bank of America also has enhanced the privacy and security sections of its Web site to include more tips about online and offline security.