A browser capable of accessing only web pages previously authorized by a parent or supervisor of a user of the browser. In a supervisor mode of operation, a parent can browse through any accessible web site and continually add approved web sites to a database of authorized web sites. Later, in a user mode of operation, the child is capable of accessing only those web sites that have been added to the authorized web site database. In the supervisor mode of operation, the browser also generates pixel signatures based on image data contained in web pages of the authorized web sites and generates checksum values based on text data contained in web pages of the authorized web sites. The browser later compares pixel signatures and checksum values from subsequently accessed web pages to the original pixel signatures and checksum values to determine if any of the data in the authorized web pages has been changed.