back up,
back make a copy of (a computer file) especially for storage in another place as a security copy; "You'd better back up these files!"
vouch give supporting evidence; "He vouched his words by his deeds"
verify confirm the truth of; "Please verify that the doors are closed"; "verify a claim"
shew,
demonstrate,
establish,
prove,
show march in protest; take part in a demonstration; "Thousands demonstrated against globalization during the meeting of the most powerful economic nations in Seattle"
document support or supply with references; "Can you document your claims?"
validate make valid or confirm the validity of; "validate a ticket"
substantiate -
make real or concrete; give reality or substance to; "our ideas must be substantiated into actions"