OpenEuphoria

Re: Encrypting Long Numbers

• Posted by Pete Lomax <petelomax at blueyonder.co.uk> Jul 12, 2003
• 630 views

Try this CK:

include sha1.e	-- http://www16.brinkster.com/davitf/
include b64.e		--
http://www.rapideuphoria.com/cgi-bin/asearch.exu?gen=3Don&keywords=3DLoma=
x

sequence t, fluff, txt

-- I assume you send it as an ascii sequence:
t=3D"12847-47844-37847-38475"=20

fluff=3D"Now CK would be real silly"&t[1..6]&
	  "if he just left this here,"&t[7..12]&
	  "instead of replacing it by"&t[13..18]&
	  "something only he knows .."&t[19..23]

txt=3Dencode64(sha_1(fluff))

printf(1,"%s\n",{txt})

-- ... send that back ...

if not equal(decode64(txt),sha_1(fluff)) then
	puts(1,"error\n")
end if

if getc(0) then end if

Providing no-one else knows what it is you do to build fluff (which
obviously needs to be the same at both ends), that should be pretty
tough to break.

Pete