Correct Usage of Security Mechanisms & Applied Cryptography

Question 1

RTTFM

Answer 1

Read The Fucking Manual

Question 2

Requirements of a Secure Connectrion

Answer 2

It is:
Encrypted
Authenticated
Tamper-proof

Question 3

Secure Connection: Encryption How?

Answer 3

Public key crypto or session keys

Question 4

Secure Connection: Authentication How?

Answer 4

Cryptographic certificates

Question 5

Secure Connection: Tamper-proof How?

Answer 5

Message Authentication Codes (MAC)

Question 6

Best practice protocol for secure connection

Answer 6

Transport Layer Security (TLS)

Question 7

Encyption

Answer 7

Transforming meaningful data into seemingly meaningless gibberish with the possibility of transforming it back

Question 8

Symmetric Encryption

Answer 8

Same key for decryption and encryption

Question 9

Chasllenge of Symmetric Encryption

Answer 9

Distribution of keys with other parties securely

Question 10

Public-Key Encryption/ Assymmetric Encription

Answer 10

Uses a public key to encrypt data and private key to decrypt data

Question 11

Hybrid Encryption

Answer 11

Asymetric Encryption to distribute symmetric key/session key and from there use symmetric encryption

Question 12

Message Authentication Codes (MAC)

Answer 12

Computes a hash for a message using a symmetric key

Question 13

Types of MACs

Answer 13

CMAC: MACs based on block cyphers
HMAC: MACs based on Hashing algorithms

Question 14

Combinations of Ciphers and MACs

Answer 14

Encrypt-then-MAC: First encrypt plaintext, then MAC the resulting ciphertext, then append it to the ciphertext. Most secure

Encrypt && MAC: Encrypt and MAC the plaintext and append the MAC to the ciphertext

MAC-then-Encrypt: MAC the plaintext, then encrypt both the tag and the plaintext

Question 15

Digital Signatures

Answer 15

Hash message and add hash
Use private key to encrypt hash
Person with public key can decrypt hash and compute the message hash
If hash match, it confirms identity of sender and integrity of message