Security

Question 1

What is Encryption

Answer 1

Scrambling data (before transmission)
So that it is meaningless if intercepted by 3rd party

Question 2

What is Symmetric Encryption

Answer 2

Encryption algorithm
Both party’s use to encrypt data
(turn plain text into scrambled/encrypted file

Question 3

What is Asymmetric Encryption

Answer 3

Public - Private Key
A key pair are generated
Public key is made available to anyone wanting to send encrypted data to owner
Private key is kept secure inside the network used to decrypt messages encrypted by its paired key (public)

Question 4

What is a Digital Certificate and what is on the certificate

Answer 4

Certificate of authenticity
… Proves the identity of a real world entity e.g. amazon
Given out by known certification authorities
Company Name
Company Public Key*
Who certifying authority
Expiry Date for certificate
Company digital signature
Certificate authorities digital signature

Question 5

What is a digital signature

Answer 5

a digital code (generated and authenticated by public key encryption) which is attached to an electronically transmitted document to verify its contents and the sender’s identity.

Question 6

Explain what https is

Answer 6

Secure channel for web communication
… Created using SSL
Encryption is used
… eg usernames, passwords
For sensitive sites e.g. payments/online banking

Question 7

What is SSL

Answer 7

Browser contact the web server
Web server will send digital certificates to browser
Browser will authenticate the digital certificate/digital signatures
If authentication fails … Terminate
IF passes
-Browser will generate a public/private key pair
-Passes its public key to web server
-Have fully encrypted communication
(Have each other public keys
You can tell SSL is used by the closed padlock located beside the https.

Question 8

Explain what Authentication

Answer 8

-Digital certificate is signed by web server
.. check sum is calculated from certificate
.. check sum is encrypted using servers PRIVATE Key
.. Attached to the certificate before transmission
-Browser used Public Key to decrypt signature
… into original check sum
-Browser recalculates checksum from digital cert
-Compares 2 checksum
-If same signature is genuine
… Not fully authenticated yet
Process is repeated using certificate authorities signatures (part of certificate)
… Browser pre-programmed with C.A. public
-When BOTH signatures are validated then authenticated is passed