Using SED/AWK to replace letters after a certain position

Question

I have a file with words (1 word per line). I need to censor all letters in the word, except the first five, with a *.

Ex.

Authority -> Autho****

I'm not very sure how to do this.

Answer 1

If you are lucky, all you need is

sed 's/./*/6g' file

When I originally posted this, I believed this to be reasonably portable; but as per @ghoti's comment, it is not.