Does such an encryption/cipher method exist? - lua

Question

while thinking of an idea to create an encryption/cipher method, I thought of one that I wondered existed already. The method I imagined was to have pre-set characters, but instead, randomly generate meanings for these characters.
Here's what I mean: (Representation in Lua)
local Keys = {'a','b','c',} -- Rest of table removed for simplicity
for i,v in pairs(Keys) do
Keys[v] = ''
repeat
if Key[v] then
Keys[v] = Keys .. string.char(math.random(1,255))
else
Keys[v] = string.char(math.random(1,255))
end
until string.len(Keys[v]) == 4
end
print(Keys) --> {'a' = "ą�vź",..}
Then when you make a string and transcribe it with the Keys table, it'll come out as the meaning given to it. Pretty simple, could probably do more with it, but does something like this already exist (have an official name for the method, perhaps?)

Answer 1

Passwordless obfuscating is also done with ROT.
Just for fun i do this...
-- rot.lua
-- Usage: Creates a table (i.e. rot) for using it with string.gsub('Hello World','(.)',rot)
-- A '.' in gsub() is neccessary to hit every single char in a string
-- ROT13 for chars, ROT5 for numbers, ROT8/ROT3/ROT2/ROT1 for signs
-- IMPORTANT: Both key/value pairs has to be datatype string
local args={...}
local rotator=function(...)
local args, rot, c ={...}, {}, ''
-- ROT5 for numbers
for i=48,52 do rot[c.char(i)]=c.char(i+5) end
for i=53,57 do rot[c.char(i)]=c.char(i-5) end
-- ROT13 for chars (upper and lower case)
-- Uppercase letters (ROT13)
for i=65,77 do rot[c.char(i)]=c.char(i+13) end
for i=78,90 do rot[c.char(i)]=c.char(i-13) end
-- Lowercase letters (ROT13)
for i=97,109 do rot[c.char(i)]=c.char(i+13) end
for i=110,122 do rot[c.char(i)]=c.char(i-13) end
-- Signs (ROT8)
for i=32,39 do rot[c.char(i)]=c.char(i+8) end
for i=40,47 do rot[c.char(i)]=c.char(i-8) end
-- Signs (ROT3)
for i=58,60 do rot[c.char(i)]=c.char(i+3) end
for i=61,63 do rot[c.char(i)]=c.char(i-3) end
-- Signs (ROT2)
for i=91,92 do rot[c.char(i)]=c.char(i+2) end
for i=93,94 do rot[c.char(i)]=c.char(i-2) end
-- Sign # and tabstop (ROT1)
rot['\t']='#'
rot['#']='\t'
return args[1]:gsub('.',rot),rot
end
local _,rot=rotator('koyaanisqatsi') -- Extracting the rot table from function rotator
if #args==2 and args[2]==':preload:' then
table.insert(rot,rotator)
return rot
else
return rotator
end -- Conditional return when required and package.preload is triggered
If required und furthermore in string table as: string.rot you can obfuscating and deobfuscating with the same function...
> myvar='koyaanisqatsi'
> print(myvar)
koyaanisqatsi
> myvar=myvar:rot()
> print(myvar)
xblnnavfdngfv
> myvar=myvar:rot()
> print(myvar)
koyaanisqatsi