EXHIBIT 2.2 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM The Board of Directors VASCO Data Security International, Inc.: We consent to the incorporation by reference in the registration statements (No. 333-62829 on Form S-8 and No. 333-46256 on Form S-3) of our report dated January 31, 2005 relating to the Balance Sheets of AOS-Hagenuk B.V. as of December 31, 2004, 2003 and 2002 and the related Statements of Operations, Cash Flows and Stockholders' Equity for each of the years in the three-year period ended December 31, 2004, which report appears in the April 20, 2005 current report on Form 8-K/A of VASCO Data Security International, Inc. /s/ BERK Accountants en Belastingadviseurs BERK Accountants en Belastingadviseurs 's-Hertogenbosch The Netherlands April 20, 2005