Nonsense. The Greeks adopted Phoenician letters. These were also used for other Semitic languages, like Hebrew, when the Torah was compiled. The ancient Greeks had no knowledge of the Torah. It has been evident to scholars for several hundred years, that Moses could not have written the
Torah, and it was not yet composed in his day - if he ever existed.
The traditional view that Moses was the author of the Torah came under increasing and detailed scrutiny in the 17th century. In 1651 Thomas Hobbes, in chapter 33 of Leviathan, cited several passages, such as Deuteronomy 34:6 ("no man knoweth of his sepulchre to this day", implying an author living long after Moses' death); Numbers 21:14 (referring to a previous book of Moses' deeds) and Genesis 12:6 ("and the Canaanite was then in the land", implying an author living in a time when the Canaanite was no longer in the land); and concluded that none of these could be by Moses. Others, including Isaac de la Peyrère, Baruch Spinoza, Richard Simon, and John Hampden came to the same conclusion, but their works were condemned, several of them were imprisoned and forced to recant, and an attempt was made on Spinoza's life.
Anyway, none of this has anything to do with the origin of the word "Britain", which you have such ridiculous notions about.