unassailable vs unshakable

unassailable and unshakable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unassailable	No	Yes	No	No
unshakable	No	Yes	No	No

As adjectives, unassailable and unshakable are synonyms defined as:

Other synonyms of unassailable include bulletproof, ironclad, watertight.

unassailable (adjective)	unshakable (adjective)
without flaws or loopholes	without flaws or loopholes
impossible to assail	marked by firm determination or resolution; not shakable
immune to attack; incapable of being tampered with