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From: Stefan Claas <pollux@tilde.club>
Newsgroups: sci.crypt
Subject: Re: base26 Encoder/Decoder
Date: Sun, 28 Apr 2024 15:45:19 +0200
Organization: i2pn2 (i2pn.org)
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Herbert Kleebauer wrote:

> But how does your base26 coding work. Take you four bytes
> of the input string and then convert this 32 bit number
> to base26 resulting in a 7 digit base26 number? There
> are 5 of this 4 byte chunks which gives a total of 35
> base26 digits. But how do you handle padding if the
> input string length is not a multiple of 4?
> 
> Or do you treat the complete string as a single number
> 0x48656c6c6f207363692e637279707421203a2d29 and convert
> this 160 bit number to a single base26 number? This would
> also result in a 35 digit base26 number, but would
> require long number arithmetic and consume a lot of
> computing power (suppose the input string is 1 MByte or
> even 1 GByte). In this case you don't have a problem
> with padding but with leading zeroes.

Sorry (I get a red face ...) The Rust code is derived
from the Python3 library without thinking to much about
the logic behind it, so I can't answer your questions
correctly!

For me it was sufficient that the code works, as expected
for small payloads, when comparing the output with the
Python3 library. The program is not intended for encoding
large (binary) payloads and only meant as a helper program
for the Diana Cryptosystem or Dein Star etc.

I am no programmer like you guys are but always appreciate
the comments! And I was in need for a binary program solution,
instead of using Python scripts, which I do not like.

> But I still don't understand the advantage over base16.
> If you only can use A-Z as transferable digits, you can
> use an alternative to the standard hex encoding:
> 
>   0  A  or Q
>   1  B  or R
>   2  C  or S
>   3  D  or T
>   4  E  or U
>   5  F  or V
>   6  G  or W
>   7  H  or X
>   8  I  or Y
>   9  J  or Z
> 10  K
> 11  L
> 12  M
> 13  N
> 14  O
> 15  P
> 
> Because there are two ways to encode 0-9, you
> can use this to send a second data stream. If
> A-J is used a 0 bit transferred and if Q-Z is used
> a 1 bit is transferred on this second channel. You
> can use this for example for a check sum or an
> error correcting code.

Thank you for explaining!

-- 
Regards
Stefan