A digital certificate is an electronic signature of either an individual and/or related entity. The digital certificate exists as a software file and is housed within web-browsers. It creates a unique identifier that can be checked by the receiver of information to provide evidence of the sender's identity and confirm that the document (if signed) has not been altered or interfered with.
Generally, the digital certificate contains two separate certificate parts (each with public and private keys): one for signing (authenticating) and another for encrypting/decrypting electronic messages.
The digital certificate is required by any person who intends to communicate with the e-Customs system.