You can use the Exclude Publisher Approvals With These Certificate Algorithms option,to disallow publisher-based approval of files whose certificates use certain algorithms.

If an algorithm is selected, files whose certificates use that algorithm cannot be approved by publisher. If an algorithm is not selected, you can use a certificate that has that algorithm to approve files by publisher. The choices are: MD2RSA, MD5RSA, SHA1RSA, and SHA256RSA. The default for new Parity installations is to allow certificates with any of the listed algorithms to be used for approvals.