Proven
Middle English: from Old French prover, from Latin probare ‘test, approve, demonstrate’, from probus ‘good’.
wiktionary
From Scottish English, as past participle of preve, a Middle English variant of prove [1] [2] – compare woven (from weave) and cloven (from cleave), [1] both of which feature -eve → -oven. Preve died out in England, but survived in Scotland, where proven developed, initially in a legal context, as in “The jury ruled that the charges were not proven.” [1] See usage notes for historical usage patterns.
Earlier, from Late Latin probō(“test, try, examine, approve, show to be good or fit, prove”, verb), from Latin probus(“good, worthy, excellent”), from Proto-Indo-European *pro-bʰuH-s(“being in front, prominent”), from *pro-, *per-(“toward”) + *bʰuH-(“to be”).
Morphologically prove + -n.
etymonline
proven (adj.)
"tried and proved," 1650s, adjective from alternative (strong) past participle, originally in Scottish legal use, of prove (v.). In this sense, Middle English had preved ("proved"), c. 1300.
