Re: The enormous potential that programming LaTeX in Ada presents.

[Simon Wright <simon@pushface.org>]

Austin Obyrne <austin.obyrne@hotmail.com> writes:

> Current cryptography is capable of encrypting ASCII and at most the
> entire Latin-1 set.

Looking back on Google I see that on 16 December 2013 I posted 
https://groups.google.com/d/msg/comp.lang.ada/qJ5vpRQarSQ/QNvyYgYVjewJ
which I've copied below.

So a year ago I demonstrated that

- minor tweaks will enable your code to:

  - deal with data on Windows and Unix systems and to transfer data
    between them, and

  - deal with binary data,

- but the cipertext is >30 times the size of the original (because you
  encode each byte of the input as 3 integers, represented as text).

These are practical matters and have nothing to do with the validity of
the encryption technology.

========================================================================
Austin Obyrne <austin...@hotmail.com> writes: 

> The transition of this crypto from Windows to Mac is quite something 
> and to my limited experience is a formidable task. 

No. 

I've put extensions at [1]; the README.txt says 

------------------------------------------------------------------------ 
The files here are intended to work with the SureCrypt software from 
http://www.adacryptpages.com. They are written against version 85610, 
and are relatively minor modifications of that software, so the 
copyright status remains that of the original (Copyright © 2003 Austin 
O'Byrne). 

There are two new programs: encrypt and decrypt. 

Encrypt usage: 

   encrypt original-plaintext ciphertext 

Decrypt usage: 

   decrypt ciphertext decrypted-plaintext 

Note that in spite of the use of the word "text" above the programs 
will work with binary data. 

The programs will work on Unix and Windows systems. Data encrypted on 
one can be decrypted on the other if required. 

Using a recent GNAT compiler, the programs can be built using the 
supplied cipher.gpr: 

   gnatmake -p -P cipher 

Simon Wright 
si...@pushface.org 
December 2013 
------------------------------------------------------------------------ 

From the software point of view, note that on Linux (which has a 
case-sensitive file system) you should use lower case for Ada source 
file names, so that, for example, Alices_Digital_Signature.ads becomes 
alices_digital_signature.ads. 

From the practical point of view, I think that the size of the encrypted 
files will be a serious issue. With the current code, they come out 
*more* *than* *30* *times* the size of the original, so that the 
encrypted SureCrypt85610.zip comes out at about 870 megabytes. Even if 
you output the encrypted data in binary the multiplier will be 12 (each 
byte of the original is encrypted as 3 integers). 

[1] https://www.dropbox.com/sh/a84i0jb8jv48nev/Q143ubNUWC 
========================================================================