Corporate data-security practices would be hit with an avalanche of new rules and information burglars would face stiff new penalties under a far-reaching bill introduced Wednesday in the U.S. Senate.

The bill represents the most aggressive--and at 91 pages, the most regulatory--legislative proposal crafted so far in response to a slew of high-profile security breaches in the last few months.

"Reforms like these are long overdue," Sen. Patrick Leahy, a Vermont Democrat, said in a floor speech. "This issue and our legislation deserve to become a key part of this year’s domestic agenda so that we can achieve some positive changes in areas that affect the everyday lives of Americans."

One portion of the bill, named the Personal Data Privacy and Security Act, restricts the sale or publication of Social Security numbers. Also, businesses would be prohibited from requiring SSNs except in a narrow set of circumstances such as obtaining credit reports and applying for a job or an apartment.

Leahy, who had hinted at his plans in a speech in March and had his personal information lost by Bank of America, is co-sponsoring the bill with Pennsylvania Sen. Arlen Specter. Because Specter is the Republican chairman of the influential Judiciary committee, the measure could move swiftly through the normally torpid legislative process.