We either accept Ephesians as scripture or we do not accept it as scripture regardless of who is the author. So, I'm not picking sides. I was curious and did a bit of research and found the following ... which I am quoting only for information only:
I also read that some believe that a later person who was very familiar with Paul's concepts wrote in Paul's name ... to give it more weight I guess.
Many terms in Ephesians aren't found in genuine Paulines but are found in the later NT writings and early patristic writings. Also, the author of Ephesians uses different words for important Pauline concepts. "Although these and related linguistic and stylistic differences alone could not prove the Pauline authorship of Eph to be impossible, they make extremely difficult the supposition that Paul could have written Eph in the form in which it has been handed down."
http://www.earlychristianwritings.com/ephesians.html
I also read that some believe that a later person who was very familiar with Paul's concepts wrote in Paul's name ... to give it more weight I guess.