VeriSign Inc, the company in charge of delivering people safely to more than half the world's websites, has been hacked repeatedly by outsiders who stole undisclosed information from the leading Internet infrastructure company.

The previously unreported breaches occurred in 2010 at the Reston, Virginia-based company, which is ultimately responsible for the integrity of Web addresses ending in .com, .net and .gov.

The VeriSign attacks were revealed in a quarterly U.S. Securities and Exchange Commission filing in October that followed new guidelines on reporting security breaches to investors. It was the most striking disclosure to emerge in a review by Reuters of more than 2,000 documents mentioning breach risks since the SEC guidance was published.