In cryptography, secret sharing or secret splitting is a method
of splitting a secret into two or more shares, so that nothing can
be said about the original secret unless one has access to a
certain number of those shares (often all). This could for instance
be used to let a number of people who don't trust each other share
a secret, to send information in a secure way or to create a puzzle
where you have to find both shares and use them to find the
geocache.
The principle of secret sharing is based on one-time pad
encryption and is very simple but can be proved to be
information-theoretically secure. It is often used to encrypt
numbers or text, but the same idea can be applied to an image as
well.
