Yes, but if you asked a Muslim, Buddhist or Atheist to sign with an X they would.

Asking a Jew to in the early 20th and late 19th century got them mad. They refused and put a circle there instead. Because the X is too close to a Christain cross.

The yiddish word for circle is kikel. You now know the origin of a slur and that unlike say, blacks, who get their worse one from the latin word for black, negra, this was something they brought entirely upon themselves.

Likewise you shouldn't believe modern Jews just follow the Biblical Old Testament, what they call the Torah. There's another set of books they follow called the Talmud, which is not the same as the Torah.