The license file in the Manco .NET Licensing System is signed using asymmetric cryptographic algorithm.
Any changes in the license file makes its signature invalid and Manco .NET Licensing System throw an exception. The signature validation uses only open key is stored with your application. Every version of every product uses own cryptographic keys. So it near to impossible to sign license file without your RSA cryptographic keys stored in your License Manager database. It makes license files strong falsification protected.