Improved techniques are directed to a method performed by a computing device of authenticating a mobile client device to a resource using location services. The method includes (a) receiving authentication requests from the mobile client device, the authentication requests each including a location freshness value indicating a respective amount of time that has passed since the mobile client device last determined its location, (b) testing the location freshness value received in each authentication request against a location freshness policy to generate a freshness result indicating whether the location freshness value complies with the location freshness policy, (c) generating an authentication response for each authentication request based at least in part on the location freshness result for that authentication request, and (d) directing the authentication response to be sent to the resource. A computerized apparatus and a computer program product for performing methods similar to that described above are also provided.