WASHINGTON (Reuters) - The U.S. government's main code-making and code-cracking agency now works on the assumption that foes may have pierced even the most sensitive national security computer ...

The FBI today challenged anyone in the online community to break a cipher code on its site. The code was created by FBI cryptanalysts. The bureau invited hackers to a similar code-cracking challenge ...

Fans of codebreaking, maths and brainteasers can now try their hand at the latest cryptic Christmas challenge set by GCHQ, the UK's intelligence agency. GCHQ released their annual Christmas card on ...

From bizarre ancient markings to random numbers and letters, codes and ciphers have been used for millennia to send secret messages, hide identities and operate outside the law. Unravelling these ...