The Trademark Clearinghouse Certificate Authority (TMCH-CA) which is operated by ICANN provides digital certificates to the Trademark Clearinghouse (TradeMark Validator -TMV certificate) which are used to sign & encrypt the SMD (Signed Mark Data) file. This is necessary to proof the heritage and ownership of the SMD file, meaning: did the SMD file actually come from the Trademark Clearinghouse. All Signed Mark Data (SMD) files generated by the Trademark Clearinghouse are signed under the TMCH-CA.
When the SMD file is presented to a third party (such as a registry or registrar), they can cryptographically decrypt and confirm the SMD file’s authenticity. Furthermore, the third party is able to confirm that the signed content was not modified since it was signed.