Customized XMLs can be encrypted to prevent end users from modifying them or for business reasons. A new HF is provided to update the encryption method because a vulnerability was found that allowed hackers to retrieve the original content. This update improves the security of encryption of these XMLs.
The HF is required both for users creating encrypted XMLs and for the recipients using them:
For those who used the earlier XML encryption it is recommended to re-encrypt the XMLs after installing the HF, distribute the newly encrypted XMLs and ask recipients to delete the earlier ones.
The new version (after the HF) can read customized XMLs encrypted by both the new and old methods.