2.8

Question 1

Cryptography

Answer 1

Authentication and access control
Confidentiality
Nonrepudiation
Integrity

Question 2

Cryptananalysis

Answer 2

Cracking encryption

Question 3

Cryptography keys

Answer 3

Added to encryption but its best to use biggest kep but sometime cant. So sometimes can hash the hashes password.. known as key stretching

There are libraries for key stretching bcrypt cypher or pbkdf2

Question 4

Cryptography lightweight

Answer 4

Iot concepts, where crpytography uses least amount of power

Question 5

Homomorphic encrpyrion

Answer 5

can perform
Calculations in encrypted form and saved in always encrypted form

Question 6

Symmetric encryption

Answer 6

1 key to decrypt and same key to encrypt, shared secret key

Cant scale, like someone carrying a key cant share one person carries

Th

Question 7

Asymmetric encryption

Answer 7

Have a public key and private key, can give to anyone share etc. only way to decrypt is with private key

So one key has one way

Question 8

The key pair

Answer 8

Asymmetric key generator creates two separate keys one is public to be shared and private stays with us

Question 9

Elliptic curve cryptography

Answer 9

Instead of numbers we use cirves to create keys, using smaller keys and use less storage and data.

Question 10

Hashes

Answer 10

Message digest, a finger print, a one way trip that cant be undone can be used to store passwords

Question 11

How to share keys privately

Answer 11

Out of band exchange, like telephone
Transit encryption like asymmetric to send symmetric

Question 12

Perfect
Forward secrecy

Answer 12

Different encryption when keys are transfer for one session, to protect and make sure multi node travel doesnt show the same key

Question 13

Steganography

Answer 13

Hide writing in an image, secirty through obscurity. The graphic is cover text.

Can do audio or video too

Question 14

Quantum computing

Answer 14

Not upgrade but to add
Value, a new way to make calculations. Instead of bits we use qubits, that exist between 1 and zero and is both

Scalability is advantage

Question 15

Quatum key distribution,

Answer 15

Sent keys in traffic with out worry cause its qubits

Question 16

Stream cipher vs block kcupher

Answer 16

Stream, encrypt one but at a tome and store one byte at a time with symmetric encryption initialization vector is added as salt

Block, one block of encryption at a time and padding is added to make sure it fits 64 or 128 bits.

Question 17

Ecb cbc ctr

Answer 17

Electronic codebook Simplest encryption mode once block until all blocks are encrytpted

Cypher block chaining easy to implement using Xored adds more randomization or initialization vector

Counter mode, starts with counter and encrypts and each block is encrpyted based on the counter

Question 18

Blockchain

Answer 18

A distributed ledger for records or replicates for everyone to see, includes payment processing digital id, supply chain monitoring etc

Question 19

Cryptography limitations

Answer 19

Speed needs to perform quick enough with the encrypt and decrypt process

Size with block cipher, bytes need
To be padded From 8 to 16 bytes if needed

Weak keys, smaller keys are weaker unless double hashed

Longevity make sure keys aren’t. Outdated

Predictability and entropy, randomization

Key reuse, can be danger but saves on resources

Resources vs security constraints