Computer Shopper 2019-11-01

ISSUE 381|COMPUTERSHOPPER|NOVEMBER 2019 113113

DNA FOR DATA ARCHIVING

data might end up in the wrong hands.
Similarly,binning CDs or DVDs
containing valuable data could be
asking fortrouble.Sowhat’s the
sensible approach to destroying data?
ForopticaldiscssuchasCDsorDVDs,
just break them in two before disposing
of them. Beware that shards of plastic
might fly intoyour eyes, so wrap it in a
towel first. Admittedly some data will
remain on both halves, but it’s certainly
not going to be readable in the normal
way, and it would be hugely expensive
to retrieve whatever might remain.
Moving on to hard disks, if you’re
paranoid, or you like playing with power
tools, you could cut the disk in two with
an angle grinder.That would certainly
do the trick, but there’s away that’s
much easier and it means that the next
owner of the PC gets afully working
machine,disk and all. That wayisto
overwritethe data, rather than just
deleting it, and there’s software
available to do just that. Bizarrely,you
might think, some of these products
can rewritethe data multiple times with
amixture of 0s, 1s and random data.

The rationale is that overwritten

data isn’t entirely overwritten. So,if

you read each bit as an analogue signal

and subtract avalue equal to the data

that has been written to it most

recently,what remains is the data

that previously occupied that portion

of the disk and perhaps even a

contribution of the data before that.

However,there’s every

indication that this is little

more than an urban myth.

Ahard disk expert once told

us that he couldn’t sayfor

sure that this had ever been

achieved. One thing’s for

sure,however: if such athing

is possible,itwill be vastly

expensive,soislikely to be

the sole domain of the

military or security forces.

In choosing secure deletion

software,therefore,wefeel

reasonably justified in

suggesting that the number

of overwrites shouldn’t be

adeciding factor.

PICKING UP THE PIECES

We might have referred to those who

are inclined to cut ahard disk into

pieces as paranoid, but some

organisations are taking no chances,

given the penalties that are available

under the Data Protection Act. Indeed,

there are plenty of companies who will

undertake to render ahard disk intoa

pile of tiny pieces, to demonstrate

that the company has taken every

means possible of making sure that

confidential data can’t leak out.

The last thing we want to do is make

computer users complacent, so we trust

our discussion of data preservation has

been something of awake-up call.

There’s probably alot more each of us

can and should do to make sure our

data doesn’t fall foul of mechanical

failure and accidents. On the other

hand, we don’t want you to panic. We

trust, therefore,that our coverage of

data recovery and data destruction has

shown you that things are often not as

bad as you might fear,and that you

might even not need to pound the hard

disk to fragments with ahammer when

you come to dispose of an old PC.

ABOVE:Youmight

like the idea of

destroying ahard

disk with apower

tool, but there

are easier ways of

ensuring your data

doesn’t fall intothe

wrong hands

DNA hasbeendescribedas the blueprint of life, the molecule that defines

the characteristics of all lifeforms onEarth.But just as natural DNAcontains

the essential information necessary forhumanreproduction,there’s potential

forsyntheticDNAto beusedasdatastorageand,insodoing,offering

unprecedented levels of datalongevity.This was demonstrated by the use of

DNA sequencingin identifyingtheskeletoninaLeicester car park as that of

Richard III. And useful information hasbeenobtained frommuch olderDNA.

Itmightsound likethestuffof science fiction,butDNA-based datastorage

has already been demonstrated in the lab,and several companies are now aiming to roll itout as

acommercial service.

Boston-based company Catalog has high hopesforthe technology.Accordingto the company’s

marketing blurb,“DNA is the digital storage mediumselectedby nature that has beenperfected

overthreebillionyearsof evolution. Itcan store millions of times more data in the same volume

as conventional solutions, can last forthousands of years, and gives you the abilityto physically

own your data–even massive amounts of it.”

RIGHT:DNA

sequencing is

escaping from the

research labs and, in

so doing, could offer

the ultimateinlong-

term data storage

LEFT:Fewpeople

believe that reading

overwritten data

from ahard disk

using an electron

microscope is

at all feasible