Peer-graded Assignment: Cryptography Case Study Answer

Cryptography Case Study

In this article i am gone to share Coursera Course: Cryptography (ISC)² | Peer-graded Assignment: Cryptography Case Study Answer with you.


Peer-graded Assignment: Cryptography Case Study Answer

Peter O’Day, Manager, Technical and Communications needs you to set up a secure communications infrastructure for remote employees that may be working from home or on the road. What can be used to support secure remote access to XYZ Network Solutions systems and data?

Policy, authentication (two factor), VPNs, logging, end user device management (encrypted hard drives, sandbox environment)


All traffic between each branch office should be encrypted automatically. Which method of encryption is best for LAN-LAN encryption? What is necessary to set this up?

IPSEC in ESP Tunnel Mode. Security Associations


As a network service provider, XYZ Network Solutions provides high speed network services via microwave to some remote locations. What type of encryption should be used on a microwave link?

Link layer encryption based on a symmetric algorithm built into hardware.


When an email is encrypted it uses a combination of symmetric and asymmetric algorithms. Why?

Symmetric algorithms are used because it has a fast and secure method of protecting the confidentiality of the email but as it use single key for both encryption and decryption, it must use asymmetric algorithms to encrypt and deliver the symmetric key. And the asymmetric algorithms can also be used for the digital signature to provide integrity of the email.


Which of the following belongs to symmetric algorithms, asymmetric algorithms and hash algorithms: AES, MD4,5, DES, IDEA, RSA, RC4,5,6 RSA MD4,5, Blowfish, Twofish, MARS, ECC, SHA1,256,512, SHA1,256,512, Serpent, Rijndael, ECC, CAST, Keccak (SHA3), Deffie-Hellman, Keccak (SHA3)

Symmetric Algorithms: AES, DES, IDEA, RC4,5,6 RSA MD4,5, Blowfish, Twofish, MARS ECC SHA1,256,512, Serpent, Rijndael, CAST Diffie-Hellman Keccak (SHA3)
Asymmetric Algorithms: RSA, ECC, Diffie-Hellman
Hash Algorithm: MD4,5, SHA1,256,512, Keccak (SHA3)


Define the following term:

  1. Plaintext
  2. Cryptogram
  3. Workfactor
  4. Digest
  5. Cryptanalysis
  6. Cryptovariable
  7. Collision
  8. Kerkhoff’s Principle
  9. Digital signature
  10. Hybrid encryption



1) Plaintext is the message in it’s. Natural format.
2) Cryptogram is the encrypted message also known as ciphertext.
3) WorkFactor is the amount of effort (both time and resource) required to defeat the cryptographic protection.
4) Digest is the hash value computed on a message by using hash function to ensure the integrity of the message.
5) Cryptanalysis is the process of defeating the cryptographic protection.
6) Crypto variable is either the key or value used by an algorithm to encrypt and decrypt or either encryption or decryption of a message.
7) Collision is the two messages that had generated the same hash or ciphertext value.
8) Kerckhoffs’s principle is the principle that only the key needs to be secret and the algorithm can be known publicly.
9) Digital Signature is used to ensure the integrity of the message and provide proof of origin (non-repudiation). But it does not provide confidentiality of the message..
10) Hybrid Encryption is use of both symmetric and asymmetric algorithms in an implementation.


What is the relationship between Steganography and Data Loss Prevention (DLP)?

Steganography Hides Data in an Image, Document, Music or Movie files To Prevent Unauthorized Access of Data. But some time it leads to loss of data as they are hidden in other files.


What are the advantages and disadvantages of symmetric and asymmetric algorithms?

Symmetric Algorithm :

  • Advantages : available for free, confidentiality fast,
  • Disadvantages : Key management or key distribution is not good as it use one key for both encryption and decryption. It only provide limited security.


Asymmetric Algorithm :

  • Advantages: Provide integrity, proof of origin, message/data authenticity, data confidentiality and provide access control
  • Disadvantages: Slow encryption or decryption and require intensive computational resources for both operations.



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