36367763ab73783c7af284446c59466b4cd653239a311cb7116d4618dee09a8425893dc7500b464fdaf1672d7bef5e891c6e2274568926a49fb4f45132c2a8b4The hash has a length of 512 bits. The hashing algorithm is not known, but potential candidates are SHA-512, BLAKE-512 or BLAKE2b.
SHA3-512 is NOT a candidate as it was released for production use after the Liber Primus was released.
It is not known what is hashed. Possible options are a URL, an image or other file or the contents of a web page. The hash can also be a unique file identifier for deep web applications such as Freenet, GnuNET or P2P file sharing systems, which use Distributed Hash Tables.