Quantum computing practically impossible

Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp> Sat, 31 October 2020 12:29 UTC

Return-Path: <mohta@necom830.hpcl.titech.ac.jp>
X-Original-To: ietf@ietfa.amsl.com
Delivered-To: ietf@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1EDF13A0888 for <ietf@ietfa.amsl.com>; Sat, 31 Oct 2020 05:29:21 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.896
X-Spam-Level:
X-Spam-Status: No, score=-1.896 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OC8DGxFY1li1 for <ietf@ietfa.amsl.com>; Sat, 31 Oct 2020 05:29:19 -0700 (PDT)
Received: from necom830.hpcl.titech.ac.jp (necom830.hpcl.titech.ac.jp [131.112.32.132]) by ietfa.amsl.com (Postfix) with SMTP id 56CC53A0880 for <ietf@ietf.org>; Sat, 31 Oct 2020 05:29:17 -0700 (PDT)
Received: (qmail 93186 invoked from network); 31 Oct 2020 12:09:39 -0000
Received: from necom830.hpcl.titech.ac.jp (HELO ?127.0.0.1?) (131.112.32.132) by necom830.hpcl.titech.ac.jp with SMTP; 31 Oct 2020 12:09:39 -0000
To: ietf@ietf.org
From: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
Subject: Quantum computing practically impossible
Message-ID: <1234528e-ef29-e81e-6c47-7bd4abb6fd53@necom830.hpcl.titech.ac.jp>
Date: Sat, 31 Oct 2020 21:28:51 +0900
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-2022-jp"; format="flowed"; delsp="yes"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/ietf/TWioB7Ylh4AJ-FC0ievOVvWV0SM>
X-BeenThere: ietf@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: IETF-Discussion <ietf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf>, <mailto:ietf-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ietf/>
List-Post: <mailto:ietf@ietf.org>
List-Help: <mailto:ietf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf>, <mailto:ietf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 31 Oct 2020 12:29:21 -0000

Let me initiate some *technical* discussion on practical impossibility
of quantum computing, here, because there is no WG in IETF for it.

QIRG is in IRTF and is chartered for, not against, quantum things.

As is discussed in:

	https://tools.ietf.org/html/draft-ohta-qec-inapplicable-00

though quantum error correction by Shor assumes that, if an entangled
state is composed as superposition of (exponentially) many unentangled
terms, all the terms are *IDENTICALLY* disturbed by noise retaining
their relative coherence, which is obviously impossible. They are  
actually disturbed *DIFFERENTLY*, correction of which is, obviously,  
impossible with constant (not exponentially many, at all) number of  
extra qubits.

As a result, quantum computing, relying on entangled states
with (exponentially) many unentangled terms, with practical
size is impossible and PKI is safe against quantum computers.

The draft is 5 pages long and requires mere elementary understanding
on entanglement.

							Masataka Ohta