Cryptography and IT Security

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Questions and Answers

What is the origin of the word cryptography?

From the Greek word 'kryptos' (correct)

From the English word 'secret'

From the Latin word 'crypto'

From the French word 'chiffrer'

What is the primary purpose of cryptography in IT security?

To provide network access control

To ensure data confidentiality and authentication (correct)

To scan for malware and viruses

To optimize system performance

What is the term for the unencrypted message in cryptography?

Cipher text

Encrypted data

Decrypted message

Plain text (correct)

What is the process of finding vulnerabilities in ciphers called?

Cryptanalysis Signup and view all the answers

What is the unknown component in the encryption and decryption process?

Cryptographic key Signup and view all the answers

What is the benefit of using larger cryptographic keys?

More secure encrypted data Signup and view all the answers

What is the purpose of cryptanalysis in cryptography?

To identify and stop using vulnerable ciphers Signup and view all the answers

What is the term for verifying that a message was sent by the person who claims to have sent it?

Non-repudiation Signup and view all the answers

What is the purpose of using multiple keys in an encryption cipher?

To add an additional level of protection to the encryption Signup and view all the answers

What is key stretching, also known as?

Key strengthening Signup and view all the answers

What is the benefit of using a key-stretching algorithm like bcrypt?

It increases the difficulty for attackers to brute force the plaintext Signup and view all the answers

What is the purpose of lightweight cryptography?

To provide cryptographic functions without high-end CPUs or power Signup and view all the answers

What is homomorphic encryption (HE) used for?

To perform calculations on encrypted data Signup and view all the answers

What is the advantage of homomorphic encryption (HE) in cloud storage?

It keeps the data encrypted while performing calculations Signup and view all the answers

What is the focus of research in lightweight cryptography?

To provide the most powerful cryptography using the least amount of power Signup and view all the answers

What is the benefit of using the bcrypt library?

It provides a simple way to generate hashes from passwords Signup and view all the answers

What is the purpose of key stretching algorithms like PBKDF2?

To make the encryption key larger and more secure Signup and view all the answers

What is the role of NIST in lightweight cryptography?

To lead the research in lightweight cryptography Signup and view all the answers

Study Notes

Cryptography Basics

Cryptography is derived from the Greek word "kryptos," meaning hidden or secret.
Cryptography provides confidentiality, authentication, access control, non-repudiation, and integrity in IT security.

Cryptography Terms

Plain text: an unencrypted message, also referred to as "in the clear message."
Cipher text: encrypted plain text using a cipher.
Cryptanalysis: the art of cracking existing encryption to find vulnerabilities.

Encryption and Decryption

A cryptographic key is added to a cipher to encrypt plain text.
Larger keys tend to create more secure encrypted data.
Using multiple keys can create another level of protection.

Key Stretching and Strengthening

Key stretching or strengthening: using a relatively small encryption key and making it larger to increase security.
Examples include hashing a password and then hashing the hash, making it difficult for attackers to brute force the original plain text.

Libraries and Algorithms

bcrypt library: generates hashes from passwords using the Blowfish cipher.
PBKDF2 (Password-Based Key Derivation Function Number Two): a library for key stretching, part of RSA public key cryptography standards.

Lightweight Cryptography

Focuses on providing cryptographic functions without high-end CPU and power.
Research led by the National Institute of Standards and Technology (NIST) for use in internet of things (IoT) devices.

Homomorphic Encryption (HE)

Allows performing calculations on encrypted data without decrypting it.
Enables storing information in the cloud in an encrypted form, and performing actions on the data without accessing the original data source.