Peter Shor has given wonderful accounts of the development of his algorithm, with a lot of detail on the activity in the field at around the early-mid 90's. He's been very free about emphasizing that his algorithm was inspired by Umesh Vazirani's ~1993 presentation at Bell Labs and especially by Dan Simon's later-developed algorithm, but I'm curious if, in particular, he conjectured that a quantum computer could factor integers ex nihilo and then developed his algorithm, or, alternatively, if the idea that quantum computers could maybe factor integers was already expressed and was part of the zeitgeist at the time...
Did anyone (...in writing) propose that a quantum computer could efficiently factor large integers before Shor developed his algorithm, or was Shor alone in guessing that it could work (and then solving it?)
The hardness of factoring and its cryptographic applications were well established by the early 90's, with PGP's 1991 release of RSA on the early, hacky world wide web. Also, quantum computers were definitely starting to be "a thing" around then as well - Greg Egan's 1992 Sci-Fi novel Quarantine has a lovely quote presupposing a quantum computer's capabilities to evaluate function in superposition.
When Deutsch and Jozsa describe their algorithm in 1992 they do mention factoring in the context of distinguishing between search problems and function evaluation problems on a classical, deterministic computer and a probabilistic computer. But, they don't seem to explicitly suppose that a quantum computer could factor large numbers.