Compilation (2)

✔CEASAR SHIFT / GRONSFELD CIPHER

Type: Substitution

> ceasar cipher or gronsfeld cipher is a type of encryption to which associated a shift of a fixed number of a letter (towards left or right). Each letter is then relaced by that obtained after performing the shift.

(Note: encoding or decoding depends on the number of shift)

Encrypt-shift forward

Decrypt-shift backward

Example:

Shift: 3

1.)LOVE

encrypted=ORYH

decrypted=ILSB

2.) JUHDW

encrypted=MXKGZ

decrypted=GREAT

✔CAESAR’S BOX

Example:
HBDY-AIAO-PRYU-PTT-YHO

(Note: arrange it like stack and read by column from top to bottom)

Stack form:

HBDY

AIAO

PRYU

PTT

YHO

Answer = HAPPY BIRTHDAY TO YOU

✔VANITY CODE

Type: Substitution

Keypad keys:

1=.,

2=abc

3=def

4=ghi

5=jkl

6=mno

7=pqrs

8=tuv

9=wxyz

0=space

Example:

356937 = flower

6676464 = morning
✔MORSE CODE

Type: Trasposition

> morse code is a system to encode thanks to short and long impulses. Each letter or punctuation mark is associated with a sequence of signals. These signals are translated to the following characters:

Dot(.) is the elementary pulse

Comma(,) represents pulse three times longer than the point

Space( ) represent separation between two letters

Vergule(/) represents separation between words

A= .-

B= -…

C= -.-.

D= -..

E= .

F= ..-.

G= –.

Η= ….

I= ..

J= .—

K= -.-

L= .-..

M= —

N= -.

O= —

P= .–.

Q= –.-

R= .-.

S= …

T= –

U= ..-

V= …-

W= .–

X= -..-

Y= -.–

Z= –..

Example:

-.-. — -. -.. .. – .. — -. = CONDITION

✔KEYWORD CIPHER

Type: Substitution

(Note: encoding or decoding is based on the keyword input)

(Note: keyword given will be inserted as first in the sequence of alphabet and letters should never repeat)

Example

Keyword: GOD

A=G N=M

B=O O=N

C=D P=P

D=A Q=Q

E=B R=R

F=C S=S

G=E T=T

H=F U=U

I=H V=V

J=I W=W

K=J X=X

L=K Y=Y

M=L Z=Z

Cipher: JMNW = KNOW

✔ROT 13

> ROT13 (“rotate by 13 places”, sometimes hyphenated ROT-13) is a simple letter substitution cipher that replaces a letter with the letter 13 letters after it in the alphabet.

Type:

A=Z

B=Y

C=X

D=W

E=V

F=U

G=T

H=S

I=R

J=Q

K=P

L=O

M=N

✔BACON CIPHER

Type: Substitution

> To encode a message, each letter of the plaintext is replaced by a group of five of the letters ‘A’ or ‘B’. This replacement is a binary encoding and is done according to the alphabet of the Baconian cipher.

A=AAAAA

B=AAAAB

C=AAABA

D=AAABB

E=AABAA

F=AABAB

G=AABBA

H=AABBB

I/J=ABAAA

K=

ABABA

L=ABABB

M=ABBAA

N=ABBAB

O=ABBBA

P=ABBBB

Q=BAAAA

R=BAAAB

S=BAABA

T=BAABB

U/V=BABAA

W=BABBA

X=BABBB

Y=BBAAA

Z=BBAAB

✔REVERSE CIPHER

Types: Words

> two modes are available in this code. First reverses the whole text, second reverses letters word by word.

Example:

1st mode

1.) NEGYXO = OXYGEN

2.) YRANOITCID = DICTIONARY

3.)1ST: REKEES NOITNETTA = ATTENTION SEEKER

4.)2nd: NOITNETTA REKEES = ATTENTION SEEKER

✔PLAYFAIR

Type: Substitution

> playfair cipher uses an array of 5×5 containing a keyword or phrase. The first step is to create a grid based on the key. The second step is to encrypt the letters of the message by selecting them in pairs.

Key: melons

(Note: grid size is 5×5 and i/j can interchange)

M|E|L|O|N

S|A|B|C|D

F|G|H|I |K

P|Q|R|T|U

V|W|X|Y|Z

Plaintext: VALENTINES

VA LE NT IN ES

Ciphertext: WSOLOUJOMA

WS OL OU JO MA

Credits to him (JB)