Unbreakable: Eight codes we can't crack

               

Unbreakable: Eight codes we can't crack

The capture of the Enigma code machine 70 years ago changed the course of the second world war. But the secret codes broken by this event were not history’s toughest ciphers. Plenty of codes are uncracked and, as MacGregor Campbelldiscovers, their solutions may provide the key to murders or even buried treasure

MURDER

Somerton Man's poetic mystery

A well-dressed man found dead on an Australian beach in 1948 wrote an indecipherable scribble in a book of Persian poetry......

TREASURE

Beale's buried treasure

Three coded messages published in 1885 hold the location of treasure buried in Virginia – or was it a hoax? We still don't know

PUZZLE

The MIT time-lock puzzle

A giant of internet cryptography has devised a code that he says will take 35 years to solve – with a mystery prize sealed in lead

CIA SECRET

Kryptos, a monument to CIA secrecy

What is the secret of a sculpture at CIA headquarters? Two decades and tens of thousands of attempts haven't broken i.....

MEDIEVAL MYSTERY

The Voynich manuscript

A medieval tome is filled with illustrations of medicinal plants, astrological diagrams, naked nymphs – and indecipherable script....

MUSICAL MESSAGE

Elgar's unread message

The composer Edward Elgar wrote a message to a friend in 1897 – in code. She never understood it, and nor has anyone else....

THE ENIGMA CODE

The second world war's last Enigma

The second world war Allies captured a German Enigma code machine 70 years ago – but many messages have never been decoded.....

ZODIAC

Who was the Zodiac killer?

The 1960s serial murderer Zodiac may have told the world his or her identity – but no one has been able to decrypt the message