Introduction To Cryptography.

INTRODUCTION TO CRYPTOGRAPHY -
D334



XOR34the34following34
0101110101010111
1001100000111010
------------------34-34answer--1100010101101101

asymmetric34key-based34encryption
-typical34methods34-34answer--RSA
DSA
El34Gamal

Symmetric34key-based34encryption
-Typical34Methods34-34answer--RC2-344034bit34key34size346434bit34block
RC4-34(Stream34Cipher)-34Used34in34SSL34and34WEP
RC5-34(Variable34Key34size,3432,3464,34or3412834bit34block34size)
AES-34(128,3419234or3425634bit34key34size,3412834bit34block34size)
DES-34(5634bit34key34size.346434bit34Block34size)
3DES-34(11234bit34key34size,346434bit34block34size)

Block34Encryption34-34answer--RC2(4034bit34key34size)34
RC5(Variable34block34size)
IDEA
DES
3DES
AES34(Rijndael)
Blowfish
twofish

stream34encryption34-34answer--RC4
Chacha

Rainbow34Attack34-34answer--
The34method34of34knowing34the34mapping34between34the34hashed34values34and34the34or
iginal34data

,Dictionary-type34attack34-34answer--a34brute34force34analysis

∉34-34answer--does34not34belong34to
when34an34object34is34not34in34a34set

∈34-34answer--Belongs34to
when34an34object34is34within34a34set

⊆34-34answer--subset
subset34has34fewer34elements34or34equal34to34the34set

A34∪34B34-34answer--union34(objects34that34belong34to34set34A34or34set34B)

|34-34answer--such34that

A34∩34B34-34answer--Intersection:34in34both34A34and34B

Enigma34Machine34-Cypher341034-34answer--
Used34a34polyalphabetic34substitution34cipher,34which34did34not34repeat34within34a34reas
onable34time34period,34along34with34a34secret34key.34For34the34cracking34of34the34Enigm
a34cipher,34the34challenge34was34thus34to34determine34both34the34algorithm34used34and3
4the34key.34Enigma's34main34weakness,34though,34was34that34none34of34the34plain34text3
4letters34could34be34ciphered34as34itself.


Four-square34cipher934-34answer--
Uses34four34534×34534matrices34arranged34in34a34square,34are34where34each34matrix34co
ntains342534letters34for34encoding34and34decoding34operations.

One-time34pad34cypher834-34answer--
Cypher34Code34mapping34that34is34only34used34once.34
Advantage:34it34is34essentially34unbreakable.34
Disadvantage:34it34takes34lots34of34work34as34you34would34have34to34generate34the34pad
34to34be34used,34each34time.


Vigenere34Cipher34734-34answer--
Polyalphabetic34cipher34that34involves34using34a34different34mapping,34based34on34a34ke
yword,34for34each34character34of34the34cipher.34An34advantage34of34this34type34of34ciphe
r34is34that34the34same34plaintext34character34is34likely34to34be34coded34to34different34map
pings,34depending34on34the34position34of34the34keyword,34making34guessing34more34diffi
cult.

Ceasar34Cipher634-34answer--Mono-
alphabetic34substitution34cipher34known34as34"shift"34cipher.34Involves34plaintext34being3
4replaced34by34a34letter34some34fixed34number34of34positions34down34the34alphabet.34i.e.
,34a34Caesar34Cipher34using34a34shift34of34+334would34mean34a34plaintext34letter34A34wo

, uld34result34in34a34ciphertext34letter34D34(a34shift34of34three34positions34to34the34right34in34
the34alphabet)

Morse34Code34cipher34534-34answer--
Encoding34method,34rather34than34a34cipher,34that34works34by34translating34characters34i
nto34sequences34of34dots34(.)34and34dashes34(-)

Playfair34Cipher34434-34answer--
534×34534matrix34containing34the34alphabet34less34the34letter34J.34Cipher/
decipher34process34consists34of34a34set34of34rules34outlining34use34of34column34and34row
34combinations.


BIFID34Cipher34334-34answer--
Makes34use34of34a34grid34and34which34maps34the34letters34into34numeric34values.

Rail34Code34Cipher34234-34answer--
Employs34a34method34to34scramble34text34by34writing34it34in34a34sequence34across34a34n
umber34of34rails.

Pig34Pen34Cipher34134-34answer--Mono-
34alphabetic34substitution34cipher34that34makes34use34of34mapping34plaintext34character
s34to34graphical34characters34rather34than34to34alphabetic34ones.34i.e.34A=(pick34a34sym
bol),34vs34A=(pick34a34letter).34Disadvantage:34once34the34mapping34is34known,34it34is34d
ifficult34to34keep34the34message34secret.

Encryption34-34answer--in34simplest34terms34is34changing34plaintext34into34ciphertext

Decryption34-34answer--The34process34of34converting34a34ciphertext34into34plaintext.

AESCrypt34-34answer--
Encrypt34individual34files34and34encrypt34full34disks34with34options34such34as34Bitlocker34
and34FileVault

Mono-alphabetic34-34answer--
c34code34or34substitution34is34where34a34single34mapping34from34our34alphabet34to34a34ci
pher34alphabet34is34created.34Many34early34cryptosystems34used34this.

Polyalphabetic34-34answer--
refers34to34the34mapping34of34our34alphabet34to34a34number34of34cipher34alphabets.34Thi
s34approach34added34a34bit34of34complexity34to34early34cryptosystems.

One-time34pad34-34answer--
is34considered34to34be34unbreakable34since34it34only34uses34its34cipher34code34once.

Pseudo-Random34Number34Generators34(PRNGs)34-34answer--
This34method34repeats34the34random34numbers34after34a34given34time34(periodic).34They