Cirrus@Austlit

'A thrilling action novel set in the not-too-distant future in which a brilliant young computer hacker fights to prevent the human race from being erased.

'It would take a very special person to crack the computer systems of the White House.
An expert.
A genius.
A devil.

'All of the above, some would say. Someone like Sam Wilson, brilliant teenage computer hacker. But Sam's obsession is about to lead him into a dangerous world. A world of espionage and intrigue; of cybercrime and imminent war. A world where logging on to your computer could mean the difference between life and death.' (Publication summary)

'Crack the code, or tomorrow is history!

Tane and Rebecca aren’t sure what to make of it. A sequence of 1s and 0s, the message looks like nothing more than a random collection of alternating digits. As they work to decode it, and the ones that follow, it slowly it becomes clear—the messages are being sent back in time from Tane and Rebecca’s future! Something there has gone horribly wrong, and it’s up to them to prevent it from happening. 

Tane and Rebecca follow the message’s cryptic instructions, but it’s not long before they begin to suspect that worst—that the very survival of the human race may be at stake...'

Source: Author's blurb.