Authenticity and Protagoras

There’s a speech in Plato’s dialogue Protagoras by the character the text is named after. About how people came to posses different attributes but that political wisdom is possessed universally and the state is based on such a fact. The question is, how much of this view can be proscribed to protagoras himself? Could we quote this as an authentic representation of views held by protagoras?

This lead to boarder questions about the authenticity within any of Plato’s text, the Socratic problem anyone?