GCHQ have published two puzzle books in the UK and one of them definitely referred to the Zodiac Ciphers, so it wouldn't surprise me if it was a hobby project o

GCHQ have published two puzzle books in the UK and one of them definitely referred to the Zodiac Ciphers, so it wouldn't surprise me if it was a hobby project of a few of them. I do strongly believe if someone had previously solved it they'd have released it though -- there's nothing damaging in these texts.