Her duress code was to use a double transposition key with precisely 18 letters, so we know this message was not sent under duress.

The Double Playfair Cipher Back to Crack the Ciphers The Double Playfair is an extension of the Playfair to use two separate keys and to encipher each pair of letters twice.

Scientists say that hiding secret messages using AI chatbots could lead to a world of iron-clad encryption.

End-to-end encryption is a system of communication where the only people who can read the messages are the people communicating. No eavesdropper can access the cryptographic keys needed to decrypt ...