What word is the opposite of "plagiarism", trying to pass off your own work as that of others?

Solution 1:

The word pseudepigraphon, plural pseudepigrapha, is a word meaning spurious writings falsely and deliberately attributed to a well-known person, usually from the past, usually in order to claim authority or credence for what is being said.

It is used particularly to refer to certain specific documents which state that they were written by an Old Testament prophet, or a Christian apostle, but which scholars and the Churches generally, do not believe were written by them.

This article Detecting pseudepigraphic texts using novel similarity measures is about a method of detecting these, with particular application to detecting plays which could be falsely attributed to Shakespeare.

There doesn't see to be an associated "ism" though.

Solution 2:

A piece of art passed off as a Picasso would be a fake, a forgery, or imitation. Fake money that pretends to be real is called counterfeit, as are Louis Vuitton handbags made on the cheap in Vietnam. So I think literary (or poetic) forgery or counterfeit should do the job. Literary hoax or deliberate misattribution might be other useful terms.