Information Technology Reference
In-Depth Information
susceptible.to.many.different.types.of.changes,.often.simply.
by.turning.on.a.computer.or.starting.up.an.application.
In. order. to. use. evidence. in. a. trial. or. for. other. uses. and.
be.sure.it.was.not.changed.in.any.way,.processes,.tools,.and.
protocols. have. to. be. carefully. followed. that. ensure. against.
these.types.of.changes.
One.often-used.tool.is.what.is.known.as.
hashing
..A.
hash.
is.a.mathematical.process.run.on.all.of.those.ones.and.zeroes.
that. make. up. a. ile.. Because. all. electronic. data. are. repre-
sented.by.the.bits.and.bytes.of.numbers.that.we.discussed.in.
other.chapters,.these.numbers.can.be.mathematically.manip-
ulated.through.a.known.hash.algorithm.that.will.result.in.a.
very.long.set.of.numbers.and.letters.in.a.hexadecimal.format..
This.long.hexadecimal.number.is.called.the.
hash
,.and.it.can.
be.made.of.a.ile.or.folder,.a.group.of.iles.or.folders,.or.even.
an. entire. hard. drive. or. other. storage. medium. (Figure 5.5)..
That.large.and.unique.number.is.like.a.ingerprint.of.what.is.
contained. in. the. data. at. that. moment.. If. someone. changes.
even. the. period.at.the. end.of. a. sentence. and. you. run. that.
same.hash.algorithm.against.the.ile.again,.the.resultant.num-
ber.will.have.changed.
Figure 5.5 A.hash.of.a.ile,.folder,.drive,.or.any.piece.of.digital.data.
is.like.a.ingerprint.
