Information Technology Reference
In-Depth Information
was.adopted.by.the.computer.world,.despite.using.the.
same.optical.disks..Ironically,.the.term.
CD-ROM
.per-
sists.despite.the.fact.that.CD.read/writers.have.been.
available.for.years.
Certiication Authority:. A.trusted.third-party.clearinghouse.
that. issues. digital. certiicates. and. digital. signatures..
Such. certiicates. include. an. organization's. name,. a.
serial.number,.and.an.expiry.date..In.addition,.and.to.
allow.for.the.encryption.and.decryption.of.data,.the.
public.key.of.the.organization.is.included..Finally,.the.
digital. signature. of. the. certiicate-issuing. authority. is.
included.so.that.a.recipient.can.verify.that.the.certii-
cate.is.valid.
Checksum:. A.technique.whereby.the.individual.binary.values.
of.a.string.of.storage.locations.on.your.computer.are.
totaled,. and. the. total. is. retained. for. future. reference..
On. subsequent. accesses,. the. summing. procedure. is.
repeated,. and. the. total. is. compared. to. that. derived.
previously.. A. difference. indicates. that. an. element. of.
the. data. has. changed. during. the. intervening. period..
Agreement. provides. a. high. degree. of. assurance. (but.
not. total. assurance). that. the. data. have. not. changed.
during.the.intervening.period.
A.checksum.is.also.used.to.verify.that.a.network.
transmission.was.successful..If.the.counts.agree,.it.is.
safe. to. assume. that. the. transmission. was. completed.
correctly.
Cipher:. The. generic. term. used. to. describe. a. means. of.
encrypting.data..In.addition,.the.term.
cipher
.can.refer.
to.the.encrypted.text..Encryption.ciphers.will.use.an.
algorithm,.which.is.the.complex.mathematical.calcu-
lation. required. to. “scramble”. the. text,. and. a. “key.”.
Knowledge. of. the. key. will. allow. the. encrypted. mes-
sage.to.be.decrypted.
Client:. A.computer.system.or.process.that.requests.a.ser-
vice. from. another. computer. system. or. process,. a.
“server.”. A. client. is. part. of. a. client-server. software.
