Virbox SDK provides "Developer Utility", the local License Manager, for developer to issue the license to hardware lock (Virbox El5) quickly. d2c API provides the interface to developer to issue license to hardware lock. Developer may call the "D2C API" to issue license with more fleixible operation and flexible to combine different license terms.

the d2c package created by d2cAPI is the only license update package which can be recognized and identified by Virbox EL5 hardware lock, d2c package includes digital signature and encryption to the license terms which will guarantee the integrity and security of license data, on the other hands, the Virbox EL5 hardware lock provides the function to anti-replay, all d2c license update package will be used  one time in the hardware lock only.

Note: Calling d2c API is quite complicate process, more details, please refer to sample file.