decoding algorithm wanted

Question

I receive encoded PDF files regularly. The encoding works like this:

• the PDFs can be displayed correctly in Acrobat Reader
• select all and copy the test vi

Answer 1

You need to brute-force it.

If those patterns are simple like +2 character code like in your examples (which is +2 char codes)

h i j
e f g
l m n
l m n
o p q

1 2 3
3 4 5
5 6 7
7 8 9
9 : ;

You could easily implement like this to check against knowns words

>>> text='jgnnq'
>>> knowns=['hello', '13579']
>>>
>>> for i in range(-5,+5): #check -5 to +5 char code range
...     rot=''.join(chr(ord(j)+i) for j in text)
...     for x in knowns:
...         if x in rot:
...             print rot
...
hello