Identifiers for XMSS:
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-10-192
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-10-256
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-10-512
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-16-192
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-16-256
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-16-512
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-20-192
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-20-256
   http://www.w3.org/2021/04/xmldsig-more#xmss-sha2-20-512
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake-10-256
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake-10-512
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake-16-256
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake-16-512
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake-20-256
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake-20-512
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake256-10-192
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake256-10-256
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake256-16-192
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake256-16-256
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake256-20-192
   http://www.w3.org/2021/04/xmldsig-more#xmss-shake256-20-256