New Scientist - UK (2022-05-21)

20 | New Scientist | 21 May 2022

Technology

Portable liquid

sunlight could

power your gadgets

A RECHARGEABLE device that stores

thermal energy from the sun and

converts it to electricity could one

day power your smartphone and

eliminate the need for batteries.

Kasper Moth-Poulsen at

Chalmers University of Technology

in Sweden and his colleagues have

designed a substance consisting

of molecules made up of carbon,

hydrogen and nitrogen that can

store solar energy for years.

The molecules change shape

when hit by light from the sun’s

ultraviolet and visible range,

trapping energy in the form of

heat. Extracting this heat returns

the molecules to their original

configuration, which can be

recharged with solar energy,

creating a renewable, closed

system. The charge is also

long-lasting, with a half-life

of up to 18 years.

The researchers initially designed

their molecules for use in a scalable,

emission-free system for domestic

heating, but have found a way to

potentially power portable devices

too by combining these with a new

thermoelectric generator developed

by a team at Shanghai Jiao Tong

University in China. Such generators

already exist at large scale, but the

Shanghai researchers have made

one that is the size of a microchip.

“They were making this heat-to-

power generator chip and we were

making the molecular solar thermal

material, and we basically combined

the two,” says Moth-Poulsen.

He and his colleagues charged

molecules in 20 millilitres of liquid

in Sweden, then shipped them to

China. The team there converted the

heat stored in the liquid into small

amounts of electricity, with minimal

heat loss, in a proof-of-concept

demonstration (Cell Reports

Physical Science, doi.org/htpr).

Moth-Poulsen says a film

version of the molecules and the

generator chip could be integrated

with a phone or tablet that had a

transparent screen to allow light

penetration. This might be possible

in the next 10 to 15 years, he says.  ❚

Rachel Parsons

UNDISCLOSED “legal

issues” are holding up a US

announcement on which

cryptographic algorithms should

be used as standard to protect data

from future quantum computers.

Meanwhile, security experts at

Google warn that data being sent

today is already at risk and that

firms need to prepare themselves

to adopt the new algorithms as

soon they are announced.

Cryptography renders

information unreadable by anyone

without the decryption key, and

modern security algorithms are

based on maths problems deemed

too hard to be cracked by even

the fastest computers available

now, including current quantum

versions. But once a large-scale

quantum computer is created,

these algorithms won’t just

become easier to crack, but trivial.

In theory, such a machine would

immediately render emails, bank

accounts and cryptocurrencies

vulnerable to attack.

Because of this, since 2017, the

US National Institute of Standards

and Technology (NIST) has been

testing 82 “post-quantum”

algorithms believed to be resistant

to the increased code-breaking

ability of quantum computers,

and whittling them down to the

best few. In March this year, the

group said that the final handful

of winners would be announced

later that month, but this deadline

has since passed.

Dustin Moody at NIST told New

Scientist that the announcement is

“no more than a few weeks” away

and that legal issues – which he

couldn’t disclose details of – were

behind the delay, although he

confirmed that a decision has

been made behind the scenes.

“There’s some lawyers involved

and they’re taking a little bit

longer to approve it than I would

have predicted,” says Moody.

Observers say companies need

to take note of the future security

risks so they can begin protecting

themselves, and us. Researchers

from Google and its spin-off

company SandboxAQ , which has

attracted investment from CIA-

linked In-Q-Tel, say that data is

already at risk of so-called store-

now, decrypt-later (SNDL) attacks,

where information transmitted

now is warehoused until a future

quantum computer can be used to

decrypt it (Nature, /doi.org/htpv).

Google says companies need

to act now because sensitive

information being sent today,

such as trade secrets, medical

records and national security

documents, could still cause

problems if revealed a decade

from now by quantum hackers.

“For those organisations that have

not started integrating PQC [post-

quantum cryptography] in their

systems or even planning for it,

we highly recommend starting

their efforts now,” writes the

team. “The SNDL attack is already

practicable, so in this context, such

organisations are already late and

at increasing risk.”

Moody says that companies

should wait for an official decision

before acting. “The risk of taking

an algorithm that isn’t our final

standardised version is you could

end up with the wrong one, and

then you end up with a product

that isn’t interoperable with what

everybody else will be [using],”

he says. “And if you’re taking

an algorithm that wasn’t on

our shortlist, there could be

security vulnerabilities.”

Although there have been

large-scale cryptography upgrades

in the past, there has perhaps

never been one as urgent as post-

quantum cryptography, says

Moody. “Part of that is because we

don’t ever know when a quantum

computer will be out there,” he

says. “Someone could make a

breakthrough next week.” ❚

Matthew Sparkes

SH

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TO

CK

/BO

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Security

Quantum-safe encryption delayed

Hitch for new security methods to keep data secure when quantum computing matures

The IBM Q is a small

quantum computer

already in use today

News

18

Number of years it takes for the

substance to lose half of its charge