univalent
In identifier systems, univalent means having a unique and non-ambiguous identifier for each entity or resource. This means that there is a one-to-one correspondence between the identifiers and the entities, and that no two different entities share the same identifier. Source: Bing chat, Sept 2023
(Paraphrased from source Universal Identifier Theory by Samuel Smith) In key management key pairs (public, private) are created in the key-pair generation and storage infrastructure and then may be moved to the key event generation and signing infrastructure in order to sign events. To protect both the key generation and storage and the event signing infrastructures. . Consequently, a given protection mechanism may co-locate both infrastructures. This means facilities are shared. This combined infrastructure is refered to as a univalent key management infrastructure.
A more secure albeit less convenient or performant univalent key management infrastructure may use special computing devices or components to store private keys and/or create signatures.