Wallets, wreckage and digital coin. Before the new year appears, let’s look at some of the most important technology stories Scientific American covered over the past 12 months.

North Korean “cyberwar” rhetoric escalates

President Barack Obama says the digital attacks in November on Sony Entertainment—allegedly by North Korea or some agent acting on its behalf—did not amount to an act of war (he referred to it as “cybervandalism”). That’s a relief, but it’s also a bit confusing, given that there’s really no internationally agreed-upon definition of what exactly a “cyberwar” is. Loose concepts didn’t stop the rhetoric, which accused Iran, North Korea, China and even the U.S. of launching such campaigns in the past year.

"One thing about war is that, historically, the lines have been drawn and there is an understanding of who the enemy is," David M. Nicol, director of the Information Trust Institute at the University of Illinois at Urbana-Champaign, said on this subject a few years ago. "When a cyber attack occurs against a sovereign state, who do you declare war on?" Perhaps we’ll find out in 2015.

New Book Cuts through Fog of Hype Cloaking Cyberwar

Apple gets into the digital wallet space

When Apple launched its digital payment service in October, the company was lending its considerable heft to a movement that could someday replace credit and debit cards. Apple Pay lets users of the iPhone 6, iPhone 6 Plus, iPad Air 2 and a number of other iOS gadgets make purchases with their devices at retailers or online. Although Google has offered a similar digital wallet for years, Apple Pay doesn’t collect transaction info or store card numbers on its devices. Despite the backing of some major retailers—including McDonalds, Nike and Petco—Apple’s approach rankled many businesses that want the mounds of consumer information that can be mined from such purchases, as is done with credit and debit card purchases. Retail giants Walmart and Best Buy, for example, rejected the Apple Pay technology and are working on a rival smartphone payment app called CurrentC.

Apple Pay Perturbs Prying Personal Prospectors

Cyber Attacks Spell the End of Magnetic-Stripe Credit Cards

Cyber currencies get big endorsements

Virtual currency had an up and down year. Bitcoin, the preeminent peer-to-peer online payment system, saw its value slashed by more than half after Tokyo-based Mt. Gox, its largest exchange, was hacked and shut down in February. Yet the fortunes of cryptocurrency have recently rebounded, driven by numerous high-profile endorsements. Apple will allow iOS developers to support the use of certain cyber coinage. Meanwhile, satellite TV provider Dish Network let its 14 million household subscribers pay their monthly bills using bitcoin. Overstock.com became the first major retailer to accept bitcoin worldwide, and even rapper 50 Cent is accepting bitcoin as payment for his latest album. The biggest endorsement yet, though, came recently from Microsoft. The software company announced in December that customers can use bitcoins to purchase certain Microsoft products, including Xbox games, music and video. Perhaps the greatest challenge that cyber currency faces in the coming year is convincing government regulators that it’s a legitimate technology used by investors for legitimate purposes rather than as a way to hide transactions from law enforcement.

What Is Bitcoin and Its Current Crisis?

Cyber Currencies Get Boost from High-Profile Endorsements

Bitcoin Vies with New Cryptocurrencies as Coin of the Cyber Realm

Technology fails missing Flight 370

More than nine months after Malaysia Airlines Flight MH370 and its 239 passengers and crew vanished en route from Kuala Lumpur to Beijing, the mystery is no closer to being solved. Despite access to the latest tracking and mapping technology available, investigators still don’t have a clear picture of what happened or even where the Boeing 777-200ER wreckage is likely to be found (there’s some consensus that it went down somewhere in the southern Indian Ocean). There was no distress call from the crew and no clear indication of bad weather or mechanical problems. Neither communications to and from the aircraft, satellite images, radar and transponder data, nor underwater sound recordings collected during search efforts have revealed clues to help solve the mystery.

Meanwhile, Australia’s Joint Agency Co-ordination Center heading the ongoing search efforts says it won’t be able to finish its sweep of the most promising patch of ocean before May. The initial search phase alone—March 17 to April 28—involved 22 military aircraft and 19 ships and covered more than 4.6 million square kilometers of ocean surface. Recent, detailed efforts have scoured more than 8,000 square kilometers of seafloor.

Mysterious Malaysia Air Flight 370 Highlights Flaws in Aircraft Tracking

How Do You Hide a Boeing 777?

Malaysia Airlines Jetliner Disappearance Likely Is Temporary

Undersea exploration advances and stumbles

After its March debut at an American Museum of Natural History exhibit, divers put an Iron Man-like cast aluminum alloy, called the Exosuit, to work. In October, divers wearing the beefy exoskeleton explored parts of the Antikythera wreckage near a remote Greek island of the same name. The treasure ship, which sank around 50 B.C., was discovered in 1900 but remains largely unexplored due to the depth of the wreckage and rough seas in that part of the Aegean Sea. The Exosuit, designed and built by Nuytco Research Limited, was to be deployed for several dives to some of the deeper spots on the wreck site, although fierce north winds forced cancellation of some of the dives, according to Philip Hilts, a science journalist who accompanied the crew during its mission. The two-meter, 240-kilogram “atmospheric diving system” allows a diver to explore down to 305 meters without succumbing to the cold and intense pressure, which is 30 times greater than at the surface. More than providing protection, the Exosuit features 1.6-horsepower foot-controlled thrusters and 18 rotary joints in the arms and legs to allow a freedom of movement impossible to achieve in even the most nimble submersible.

Not all undersea exploration news was good, however. In May the Nereus robotic submersible imploded while exploring the Kermadec Trench, a 10-kilometer rut deep in the Pacific Ocean floor where two tectonic plates meet northeast of New Zealand. Researchers at Woods Hole Oceanographic Institution (WHOI) built the high-tech, remotely operated vehicle to withstand pressure in excess of 1,125 kilograms per square centimeter. Yet it was roughly that amount of pressure that likely imploded a portion of the sub. WHOI had outfitted its foremost explorer of the ocean’s hadal zone—below six kilometers—with technology designed specifically for filmmaker and aquanaut James Cameron’s historic solo dive to the Challenger Deep, the deepest place in the world’s oceans

Return to the Antikythera Shipwreck: The Exosuit’s First Mission

Iron Man-Like Exosuit to Expand Ocean Exploration [Video]

Submersible Dives Deep and Dies, Disheartening Scientists

Honorable Mention:

Physicist Stephen Hawking gets an upgrade to the technology that enables him to communicate with the world.

The European Union grants the right to be forgotten on the Internet; Google receives 12,000 requests the first day the page went live.