From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 2002:a24:e181:: with SMTP id n123-v6mr6601108ith.23.1541433830425; Mon, 05 Nov 2018 08:03:50 -0800 (PST) X-Received: by 2002:aca:50c4:: with SMTP id e187-v6mr31858oib.7.1541433830287; Mon, 05 Nov 2018 08:03:50 -0800 (PST) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!news.gegeweb.eu!gegeweb.org!fdn.fr!proxad.net!feeder1-2.proxad.net!209.85.166.216.MISMATCH!g188-v6no335982itg.0!news-out.google.com!n199-v6ni428itn.0!nntp.google.com!g188-v6no335981itg.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Mon, 5 Nov 2018 08:03:49 -0800 (PST) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=2a00:23c0:8889:5d00:ecad:e1f0:bce1:ea52; posting-account=pmkN8QoAAAAtIhXRUfydb0SCISnwaeyg NNTP-Posting-Host: 2a00:23c0:8889:5d00:ecad:e1f0:bce1:ea52 References: <514a0be1-2445-4450-91ad-3ddd38e84032@googlegroups.com> <85190071-b0f4-4c40-b178-7630c1caaa17@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <15b1f501-28ab-4430-be7d-32f8f15fbf05@googlegroups.com> Subject: Re: Problem Cross - Posted fron Sci Crypt Crypto Group From: Austin Obyrne Injection-Date: Mon, 05 Nov 2018 16:03:50 +0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Xref: reader02.eternal-september.org comp.lang.ada:54768 Date: 2018-11-05T08:03:49-08:00 List-Id: On Monday, November 5, 2018 at 8:19:52 AM UTC, Simon Wright wrote: > Austin Obyrne writes: >=20 > > Having thought it through again for the umpteenth time I realise now > > that my problem is to do with integer overflow i.e. integers greater > > than 2^31. I am using 32-bit computer architecture. >=20 > Not sure whether so old a compiler would support declaring 64-bit > integer as >=20 > subtype Austins_Integer is Long_Long_Integer; >=20 > or possibly, to make it more explicit, >=20 > type Austins_Integer is range -2 ** 63 .. 2 ** 63 - 1; Hi again Simon, I think I would like to become familiar with 64-bit working as a useful too= l but for my present needs what I have is OK. I am able to create totally i= ntractable ciphertext on the back of using plane geometry and vector arithm= etic combinations. A point to be taken into account is the ciphetext-to-plaintext expansion ra= tio and the effect this has on transmission costs to the secure comunicatio= ns industry so that larger integer overflow capacity as you outline is not = that important. My personal attitude is security at all costs and I am not very sympathic t= o that side of things but I must try however to reduce the size of the ciph= ertext items i.e. the size of the coefficients of the physical vectors that= are the transformations of the plaintext items into ciphertext. I think I am on track now to achieving the ploy of scrambling the ciphertex= t as de rigueur practice in the industry. This makes it possible to discon= tinue my present modus operandi of using a change-of-origin that is given a= s an addition to the computed ciphertext in order to make it intracable. T= hat unfortunataely causes quite large ciphertext expansion which as I say i= s expensive. Scrambled ciphertext makes it easier to obfuscate the plaintext and even th= e most benign are made very strong - no need for highly sophisticated glamo= urised algorithms any more. Many thanks again for your help. Austin.=20