British spies could be offered a James Bond-style smartphone app after a UK company devised what it believes to be the world's first totally secure messaging service.
The secret technology uses complex ciphers to send heavily encrypted messages from one iPhone to another without passing through any central servers - and is being offered straight off the shelf for £3.99.
Designers are so convinced by its levels of security that they have challenged hackers to crack its codes and have offered a £10,000 prize to anyone who can intercept a message.
It is hoped the app, designed by the British firm Redact, based in Geneva, could become the latest asset in the world of espionage.
The company has already offered its Secure Messenger service for free to MPs and submitted the technology to CESG, the Government's National Technical Authority for Information Assurance, which provides advice on the security of communications and electronic data.
Redact is confident its technology is more resistant to hacking attempts than other systems in use.
It believes no off-the-shelf app has ever been granted CESG approval before.
A message on the Redact website reads: "We're confident that the messages you send via the Redact app are completely secure.
"To prove it, we are offering a standing reward of £10,000 to anyone who has the skills to intercept and decrypt a challenge message, which constantly bounces between two phones in our challenge location."
It has promised to give anyone willing to take on the challenge a head start by giving them the location of the phones.
The Redact app is designed so any messages - both sent and received - can be removed from both handsets at the touch of a button with no method of recovery.
If one user chooses to erase a message, it will also be eradicated from the sender or recipient's device and apparently deleted forever.
Redact said: "All instant messaging apps store messages you're sending to your contacts.
"No matter how securely these messages are saved, they're vulnerable to hackers or government subpoenas.
"Redact stores no messages, contact information or usernames so there is no information to be stolen."
The company said its app would never asks for a user name, email or phone number and that a customer's real name could never be accessed by their contacts.
Instead, anyone using the app would be assigned a unique pin number which is never stored.
Redact added: "There is no recovery tool for hackers to exploit. Only you can change your alias, so you can be certain contacts aren't using your real name anywhere in the application."
The firm said it was developing the technology for phones that use Google's Android operating system.
Currently the app can only work between iPhones.
Would-be hackers can submit an application to take on the Redact challenge at http://www.moderndayturing.com.