The power of a slave's name?

[Stephen]

The legionnaire-conscript know as "The Man from the North," is captured - and thus enslaved - by the Jews on Masada. As a slave he had no status of "person-hood" in the eyes of law and custom, and as such had no personal name or identity -- he was referred to as what his masters called him.

So it is rather unusual that he would reveal his personal name to the women of the dovecote (this happens in a later chapter). I found interesting the way Hoffman emphasizes this ... she couches it as "extraordinary" in that revealing his name is an act of "intimacy" that would either not typically be surrendered by the slave, or accepted by his/her masters.

It's known that possessing a person's name held a certain superstitious power in this era, believed to be useful in invoking sympathetic magic, binding a blessing or a curse to the named, etc. But I'm curious -- Hoffman's particular take on it, a slave revealing his personal name as "intimate," as if offering up the only thing left that he owned -- is this a research-related interpretation, is it based on an actual taboo or belief of the time, or is it a creation of the author's literary license?