100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Previously searched by you
Previously searched by you
logo
WGU C839 Objective Assessment Study Guide (Latest 2024/ 2025 Update) Introduction to Cryptography| Qs & As| Grade A| 100% Correct (Verified Answers) £8.97   Add to cart
Quickly navigate to
Preview
  2.  
  3. WGU C839
  4.  
  5. WGU C839

Exam (elaborations)

WGU C839 Objective Assessment Study Guide (Latest 2024/ 2025 Update) Introduction to Cryptography| Qs & As| Grade A| 100% Correct (Verified Answers)
 8 views  0 purchase
  • Module
  • WGU C839
  • Institution
  • WGU C839

WGU C839 Objective Assessment Study Guide (Latest 2024/ 2025 Update) Introduction to Cryptography| Qs & As| Grade A| 100% Correct (Verified Answers) Q: Information Theory Answer: -Published by Claude Shannon in 1949 in the Bell System Technical Journal - Important concepts: -Diffusion ...

[Show more]

Preview 4 out of 66  pages

Document information

  • October 13, 2024
  • 66
  • 2024/2025
  • Exam (elaborations)
  • Questions & answers

Subjects

  • serp
  • wgu c839c839 introduction to cryptographyc839 oa
  • c839wgu c839 introduction to cryptographyc839 pa
  • c839c839 introduction to cryptographywgu c839 oa
  • wgu c839 objective assessment study guide latest

Written for

  • WGU C839
  • WGU C839

Seller

avatar-seller
nurse_steph

Reviews received

Content preview

WGUIC839IObjectiveIAssessmentIStudyI
GuideI(LatestI2024/I2025IUpdate)I
IntroductionItoICryptography|IQsI&IAs|I
GradeIA|I100%ICorrectI(VerifiedIAnswers)

Q:IInformationITheory
Answer:
-PublishedIbyIClaudeIShannonIinI1949IinItheIBellISystemITechnicalIJournal
-IImportantIconcepts:
I-Diffusion
I-Confusion
I-AvalancheIEffectI(HorstIFeist'sIvariationIonIShannon'sIconceptIofIdiffusion

Q:IKerckhoff'sIPrinciple
Answer:
-1883
-
AIcrptosystemIshouldIbeIsecureIevenIifIallIitsIelementsIofItheIsystem,IexceptItheIkey,IisIpubli
cIknowledge

Q:IFeistelINetwork
Answer:
-AIcryptographicIprimitiveIthatIformsItheIbasisIofImanyIsymmetricIalgorithms.I
-
FeistelInetworksIcombineImultipleIroundsIofIrepeatedIoperations,IsuchIasIprocessingIcleartextI
inputIwithIXORIfunctions.I
-AIkeyIscheduleIisIusedItoIproduceIdifferentIkeysIforIeachIround.
-StartsIbyIsplittingIplaintextIdataIintoItwoIparts
I-L0IandIR0
-UsuallyIsplitIequallyIbutInotIalways
-UnbalancedIFeistelICipherIusesIaIsplitIthatIisIunequal
-TheI"roundIfunction"IFIisIappliedItoIoneIofItheIhalfs

,-
TheItermIroundIfunctionIrefersItoIaIfunctionIperformedIwithIeachIiterationIofItheIfeistalIcipher
-TheIoutputIofIeachIroundIfunctionIFIisIthenIXORedIwithItheIotherIhalf
-
TheImainIdifferenceIbetweenIcryptographyIalgorithmsIisItheIexactInatureIofItheIroundIfunctio
nIF,IandItheInumberIofIiterations

Q:IDataIEncryptionIStandardI(DES)
Answer:
-64IbitIalgorithm
-OperatingIatI56-bits
-8IbitIparityIblocks
-SymmetricIKeyIAlgorithm

Q:IDataIEncryptionIStandardI(DES)IOperation
Answer:
-I1.IDataIisIdividedIintoI64IbitIblocks
-2.IThatIdataIisIthenImanipulatedIbyI16IseparateIstepsIofIencryptionIinvolving:
I-Substitutions
I-Bit-Shifting
I-LogicalIoperations
I-UsingIaI56IbitIkey
-I3.IDataIisIthenIfurtherIscrambledIbyIusingIaIswappingIalgorithm
-I4.IDataIisIfinallyItransposedIoneIlastItime
-NSAITypeI3Ialgorithm

Q:IDESIS-Boxes
Answer:
-IDESIusesI8I"S-boxes"
-S-BoxesIareISubstitutionIBoxes
-S-BoxesIareIbasicallyIlookupItables
-EachIS-BoxIhasIaItableIthatIdeterminesI(basedIonItheIbitsIpassedItoIit)
I-WhatItoIsubstituteIforIthoseIbitsIfor
-EachIitemIpassedIintoItheIboxIisIsubstitutedIwithItheIitemIthatImatchesIitIinItheIlookupItable
-EachIoneIofItheIDESIS-boxesItakesI6IbitsIandIproducesI4Ibits
-TheImiddleI4IbitsIofItheI6IbitIinputsIareIusedItoIlookupItheI4IbitIreplacementIbits

Q:I3DESI(TripleIDES)

,Answer:
-ISymmetricIKeyIAlgorithm
-TypeI3IAlgorithmI(NSA)
-IAppliesIDESIthreeItimes
-I168-bitIkeyI(+24IforIparity)
-IUsesIaI"keyIbundle"
-KeyIbundleIhasI3IDESIkeys
I-k1
I-k2
I-k3
-EachIkeyIisIstandardI56-bitIkey
-DESIencryptsIwithIk1
-DecryptsIwithIk2
-ThenIencryptsIagainIwithIk3

Q:IDESx
Answer:
-SymmetricIalgorithm.I
-64IbitIkeyIisIappendedItoIdata,IXORIit,IandIthenIapplyItheIDESIalgorithm.
-
VariationIofIDESIthatIXORsIanotherI64IbitIkeyItoItheIplaintextIbeforeIapplyingItheIDESIalgor
ithm
-IUsesIWhitening
-AddItoItheIconfusionIofItheIresultantItext

Q:IWhitening
Answer:
-TheIconceptIofIsimplyIXORingIinIanIadditionalIkeyItoIaddIconfusion

Q:IAdvancedIEncryptionIStandardI(AES)
Answer:
-IAIsymmetricIcipher
-Rijndael
-ReplacedIDESIasIofI2001
-IthatIwasIapprovedIbyItheINISTIinIlateI2000IasIaIreplacementIforIDES.
-FormallyIannouncedIbyINISTIasIFIPSI197
-UsedIaIsubstitution-permutationImatrix
I-InsteadIofIaIFeistelInetwork

, -OperatesIonIaI4x4IcolumnImajorIorderImatrixIofIbytes
I-CalledIstates

Q:IAdvancedIEncryptionIStandardI(AES)-KeyIsizesIandIblockIsize
Answer:
-AES128I(128-bits,I128IbitIblockIsize)
-AES192I(192-bits,I128IbitIblockIsize)
-AES256I(256-bits,I128IbitIblockIsize)

Q:IAdvancedIEncryptionIStandardI(AES)-Operation
Answer:
-1.IKeyIexpansion
I-RoundIkeysIareIderivedIfromItheIcipherIkeyIusingIRijndael'sIkeyIschedule
-2.IInitialIround:
I-AddRoundKey
I-EachIbyteIofItheIstateIisIcombinedIwithItheIroundIkeyIusingIbitwiseIXOR
-3.IRoundsI
I-SubBytes
I-
AInonIlinearIsubstitutionIstepIwhereIeachIbyteIisIreplacedIwithIanotherIaccordingItoIaIlookupI
table
I-LookupItableIisIcalledIaIRijndaelIS-Box
I-ShiftRows
I-
AItranspositionIstepIwhereIeachIrowIofItheIstateIisIshiftedIcyclicallyIaIcertainInumberIofIsteps
I-MixColums
I-
AImixingIoperationIwhichIoperatesIonItheIcolumnsIofItheIstate,IcombiningItheIfourIbytesIinIe
achIcolumn
I-AddRoundKey
4.IFinalIRoundI(noIMixColumnsIused):
I-SubBytes
I-ShiftRows
I-AddRoundKey

Q:IBlowfish
Answer:
-ISymmetricIcipher
-FeistelICipher

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller nurse_steph. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £8.97. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

75632 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now

Start selling
£8.97
  • (0)
  Add to cart