Use the simplest way of testing diploma request in a school that the diploma is issued, the data and check the number. Often schools do not provide this information, citing its confidentiality, then one option for you - write an official letter on the letterhead, which specify scan targets with the signature of the owner of the diploma and note that it agrees with the audit. After some time (usually a week) you will receive an official response.
If you have friends in the police, ask them to check the authenticity of this document through their own channels.
Use for authentication of the diploma of social networks such as Odnoklassniki and Vkontakte. They have large databases of training institutions, it is possible to find fellow students of the applicant and to find out all about them - you know such a person, whether studied together.
In the near future, the employer will be able to establish the authenticity of diplomas through an electronic database of its employees. Such decision was accepted the Ministry of education. "Today we build an information database that will answer these questions", commented the Minister Fursenko.