Cipher

[Serious475]

I want to share some cipher that I learned in our university, here are some of it.

SUBSTITUTION CIPHER
This cypher is you will indicate one value into another value let’s say with the English Alphabet.

Example:
ABCDEFGHIJKLMNOPQRSTUVWXYZ

You want to start with the encryption four-letter add.

Encryption :
EFGHIJKLMNOPQRSTUVWXYZABCD

I want to encrypt with the name of

Plain text: SAD
Encryption text: WEH

VERNAM CIPHER
You will arrange the letter with the corresponding number.

A = 0
B = 1
C = 2
D = 3
E = 4
F = 5
G = 6
H = 7
I = 8
J = 9
K = 10
L = 11
M = 12
N = 13
O = 14
P = 15
Q = 16
R = 17
S = 18
T = 19
U = 20
V = 21
W = 22
X = 23
Y = 24
Z = 25


Example:

Plain text: B I T C O I N
Assigned number: 1 8 19 2 14 8 13
KEY: B T T C O I N
Assigned number: 1 19 19 2 14 8 13

Add the assigned number if the sum of the two number exceed on 26 you need to subtract it to 26.
1 8 19 2 14 8 13
1 19 19 2 14 8 13

Answer : 2 27 36 4 28 16 26

The highlighted number meet 26 and above so they need to subtract and this is the new cipher text now.

Answer : 2 1 10 4 2 16 0

In plain text C B K E C Q A

BOOK CIPHER
This kind of cipher requires to have a book, we need right here is the page number, line number, and word number.

Example:
2.4.1

First number = Page number
Second number = Line number
Third number = Word number

So we can access all let’s try this reference [1] Titled: Bitcoin and Cryptocurrency Technologies

2.3.1

Page 2
Line 4
Word 1

The answer is Bitcoin.

RUNNING KEY CIPHER
To use this we need the Vigenère cipher this table called Vigenère square or Tabula recta

This is how a  Vigenère cipher looks like.

The same concept with this instead you need to use a word to decrypt the message.

Example:

BITCOINTALK
BTTCOINTALK
-------------------
CBMECQAMAWU

I have some sMerit also I want to challenge other members too to try this.
To a newbie - member rank you can join and chance to get sMerit
To Full member above you can join too.

For sure someone will try to make a copy-paste but are you sure that that's correct?. Good luck!.

CHALLENGE

SUBSTITUTION CIPHER
ABCDEFGHIJKLMNOPQRSTUVWXYZ
EFGHIJKLMNOPQRSTUVWXYZABCD

Encrypt the plain text: FORUM


VERNAME CIPHER

Plain text: FORUM
Assigned key: ?
Key text: COINT
Assigned key: ?

Encrypted text: ?
Assigned key: ?


BOOK CIPHER
Still the same source[1] find the word we are looking for with this code
5.2.4

Word : ?

RUNNING KEY CIPHER
HAPPYFORUM
HOLIDAYSFN
--------------
??

Code:

Source: 
https://www.geeksforgeeks.org/vernam-cipher-in-cryptography/
[1] https://www.lopp.net/pdf/princeton_bitcoin_book.pdf
http://practicalcryptography.com/ciphers/running-key-cipher/
https://www.youtube.com/watch?v=Lk_RpszwQvE

Other cipher threads on our forum
[INFORMATION] The Cipher, it's meaning, types and connection in cryptography
Introduction to modern cryptography.

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[Insanerman]

I have some sMerit also I want to challenge other members too to try this.
To a newbie - member rank you can join and chance to get sMerit
To Full member above you can join too.

Honestly, you intentions to share your merits to newbies was good. Yet, there are already arguments with regards on giving merits just because of following some challenges (I've forgotten the main thread that talks about it, but AFAIK there was). As far as I can remember, the claims on why such merit-giving threads is being opposed is because merit was made as a point-system like that dictates if you are a quality poster, a funny one, and/or an informative one, IN WHICH, opposes the idea of doing easy challenges would make you rank up, even if your pasts posts were trash and spams. (no hate, just opinions)

One flaw I found in the OP is that Sub-Cipher example is wrong. SAD is WEH when encrypted. Another additional flaw with this idea, is that these ciphers does have an online tool (im sorry), hence everyone can get merit for a challenge they've just searched.

[Serious475]

Snip

Thank you for your concern and insight well I'm open with this kind of criticism, I just want to share some information at the same time to seek some fun with the use of challenge I do not give all of my sMerit just to limited people but still if they want to continue to try this even without merit they can freely do it.

Changes applied to thank you again.

[Cadaver20]

I first learned this. I don't know if I have learned at all. What's wrong with trying.

CHALLENGE

SUBSTITUTION CIPHER
ABCDEFGHIJKLMNOPQRSTUVWXYZ
EFGHIJKLMNOPQRSTUVWXYZABCD

Encrypt the plain text: FORUM
Encryption text: JSVYQ
VERNAME CIPHER

Plain text: FORUM
Assigned key: 5 14 17 20 12
Key text: COINT
Assigned key: 2 14 8 13 19

Encrypted text: H C Z H F
Assigned key: 7 2 25 7 5

BOOK CIPHER
Still the same source[1] find the word we are looking for with this code
5.2.4

Word : MojoNation

RUNNING KEY CIPHER

I don't understand it. Can you explain it in details?