Cissp Cybrary 03 Part 2

Front 1

Caesar cypher

Back 1

Shift each letter 3 spaces

Front 2

Scytale, scyrod?

Back 2

Wrap paper around rod, then type message. Diameter is the key.

Front 3

Vignere cipher

Back 3

Have a table

ABC

A:ABC...

B:BCD...

C:CDE...

...

First letter of the key is matched with the first letter of the message which encodes the msg.

Front 4

Enigma machine and purple machine

Back 4

Rot based systems to change the system.

Front 5

Vietnam cipher

Back 5

One time pad. Only mathematically unbreakable form of cryptography.

Key must be used only once

Pad must be at least as long as the msg

Key pad is statistically unpredictable

Keypad must be delivered and stored securely

Ex: session keys and one time passwords

Front 6

Non-repudiation

Back 6

Combines authenticity and integrity.

Front 7

Confusion

Back 7

Complex substitution

Front 8

Avalanche

Back 8

One Change in plaintext causes multiple changes in cipher text.

Front 9

Open - Kerckhoffs principle

Back 9

Two pieces. Algorithm and key. Principle says that algorithm should be public but key should be secret.

Front 10

Name one symmetric stream algorithm

Back 10

RC-4

Front 11

Name one symmetric block algorithm

Back 11

AES or 3DES

Front 12

The default crypto algorithm in most applications

Back 12

AES

Front 13

Email service pretty good privacy uses crypto algorithm

Back 13

IDEA. (Think pgp is a good idea)

Front 14

Drawbacks with symmetric keys

Back 14

Out of band key exchange (how to exchange keys)

Not scalable N*(N-1)/2

No Authenticity, Integrity or Non-repudiation

Front 15

Positive sides with symmetric keys

Back 15

It is fast

Front 16

How to get privacy in message

Back 16

Use receivers public key

Front 17

How to get authenticity in msg

Back 17

Encrypt with senders private key. Prove that the sender encrypted it

Front 18

Non repudiation

Back 18

Integrity and authenticity

Front 19

How to get integrity in msg

Back 19

Sender saves the hash of the message and sends it with the msg.

Receiver calculates the hash of msg and compares it with the hash that the sender sent.

Front 20

How to get non repudiation in msg

Back 20

Sender hashes the message. Then encrypts the hash with senders private key.

The receiver calculates the hash of the received msg. The receiver decrypts the received hash with the senders public key. Then compares the hash. The encryption gives authenticity and the hash gives integrity. In total we get nonrepudiation.

Front 21

SSL/TLS hybrid cryptography

Back 21

Client encrypts the the data with the symmetric session key.

Then encrypts the session key with the servers public key.

The server decrypts the session key with its private key.

Decrypts the data with the session key.

Front 22

Number of keys in a symmetric environment

Back 22

N*(N-1)/2

Front 23

Number of keys in a asymmetric environment

Back 23

2N

Front 24

Symmetric keys are used for

Back 24

Bulk encryption. I.e. encrypting files and communication paths

Front 25

Asymmetric keys are used for

Back 25

Encrypting keys and distributing keys

Front 26

Symmetric keys gives

Back 26

Confidentiality

Front 27

Symmetric keys gives

Back 27

Confidentiality

Front 28

Asymmetric keys gives

Back 28

Confidentiality, authentication and non-repudiation

Front 29

Symmetric algorithms

Back 29

DES, 3DES, AES, RC-4, RC-5, two fish, blowfish, IDEA, CAST, MARS

Front 30

Asymmetric algorithms

Back 30

DSA, RSA, ECC (elliptical curve cryptography), El gamal, Diffie Hellman, Knapsack

Front 31

Algorithm used in Digital signatures

Back 31

RSA, uses factorization

Front 32

Diffie Hellman

Back 32

Secure key agreement without presented secrets, uses modulus and fields.

Front 33

ECC

Back 33

Elliptical curve cryptography. Very fast. Used in handheld devices (limited process capabilities). Based on plotting points on a curve

Front 34

Collision

Back 34

Two documents gives the same hash

Front 35

Birthday attack

Back 35

Based on the idea that two documents gives the same hash instead of producing a specific hash

Front 36

MD-5 bit lengt

Back 36

128

Front 37

SHA-1 bit length

Back 37

160

Front 38

SHA-256 bit lenght

Back 38

256

Front 39

Digital signature

Back 39

When the sender encrypts the hash with its private key.

Then the receiver can decrypt the hash the the senders public key.

Front 40

PKI

Back 40

Public key infrastructure.

Certificate authority CA

Registration Authority

Certificate repository

Certificate revocation list

Front 41

MAC

Back 41

Message authentication code. A messages that is hashed with a symmetric key.

Front 42

HMAC

Back 42

The algorithm to produce the MAC (msg+symmetric key+algorithm).

Front 43

Which standard is used in certificates?

What do they provide?

Back 43

X.509 v.4

Authenticity of servers public key. To avoid MITM attacks.

These are digitally signed by a Certificate Authority.

Front 44

Certificate revocation list CRL

Back 44

CA publish a CRL which contains certificates that has been revoked.

Front 45

Certificate revocation list CRL

Back 45

CA publish a CRL which contains certificates that has been revoked.

Front 46

OCSP

Back 46

Online certificate status protocol. Streamlined the process of verifying whether or not a certificate has been revoked.

Front 47

Registration authority

Back 47

Helps the certificate authority

Front 48

IPSEC

Back 48

Encapsulation framework. Wrapping security around the packages.

Front 49

Tunnel mode

Back 49

IPSsec header: (not encap.)

IP header: Encapsulated

IP payload: Encapsulated

IP trailer: Encapsulated

IPSec trailer: (not encap.)

Front 50

Transport mode

Back 50

IPSsec header: (not encap.)

IP header: (not encap.)

IP payload: Encapsulated

IP trailer: (not encap.)

IPSec trailer: (not encap.)

Front 51

IPSec sun protocols

Back 51

AH - Authentication header

ESP - encapsulating security payload

IKE - Internet key exchange

Front 52

IPSec sun protocols

Back 52

AH - Authentication header

ESP - encapsulating security payload

IKE - Internet key exchange

Front 53

AH

Back 53

Authentication header. Gives integrity, authenticity and non repudiation. Hashing headers.

Does not work with NAT.

Front 54

ESP

Back 54

Encapsulation security payload. Gives authenticity, integrity and confidentiality. Encrypts the payload.

Front 55

IKE

Back 55

Internet key exchange. Management of secure connection.

- Oakley uses Diffie Hellman to agree upon a key

- ISAKMP manages keys

Front 56

SPI

Back 56

Each connection (both in and out) in IPSEC has a

- destination address

- SPI (security parameter index)

which together gives the security association. This is a socket.

Front 57

Chosen plaintext

Back 57

Attacker has captured the encrypted text

Front 58

Known plain text attack

Back 58

Attacker has captured the encrypted text and some portion of plaintext.

Front 59

Chosen plaintext attack

Back 59

Attacker has captured the encrypted text and the plaintext.

Front 60

Chosen ciphertext attack

Back 60

Attacker can see whatever they want. They have compromised a workstation. (Often called a lunchtime or midnight attack)

Front 61

Meet in the middle attack

Back 61

Attacker tries to learn what the keys are used for. How does each key encrypts the msg in each step.

Usually target against 3DES.