The security software vendor Vasco Data Security International Inc. said Monday that it bought the Internet trusted services company DigiNotar BV for $12.9 million.

Vasco, of Oakbrook Terrace, Ill., said it expects the acquisition of the Dutch company to help it advance its digital signature and public key infrastructure products.

DigiNotar is an official Dutch certification authority, meaning it can issue, validate and register identities of Dutch national and entities that are recognized throughout the European Union.

"DigiNotar provides Vasco with a strong foothold in the Dutch eGovernment market with the potential to expand the product line to government applications in other countries," Vasco said. Vasco paid for the acquisition using existing cash balances.