{"id":1114,"date":"2005-11-01T14:15:54","date_gmt":"2005-11-01T21:15:54","guid":{"rendered":"http:\/\/dabacon.org\/pontiff\/?p=1114"},"modified":"2005-11-01T14:15:54","modified_gmt":"2005-11-01T21:15:54","slug":"1114","status":"publish","type":"post","link":"https:\/\/dabacon.org\/pontiff\/2005\/11\/01\/1114\/","title":{"rendered":"Superpositions of Worms Going In and Out"},"content":{"rendered":"

Over at Fact and Fiction<\/a> there is an interesting post<\/a> about an article in New Scientist called Attack of the Quantum Worms<\/a>.
\nHaving not read the article, I thought I’d be an idiot and comment on what one could possibly mean by the statement that quantum computers are more susceptible to malicious attacks. I’m an even bigger idiot because I know very little about computer software security. But life’s about saying silly things and then getting chewed out by all you smart people, know?
\nThe first thing one might mean is that quantum data cannot be backed up due to the no cloning theorem. OK, suppose I’m a hacker who wants to attack your quantum computer. Surely if I write some code which is executed by the computer and it damages the quantum state of the system, then, because I can’t back up the state of the quantum computer, I’m in big trouble. So it seems that one cannot prevent crashing a quantum computation by backing the state of the system up. But this isn’t quite right, is it? I mean suppose we have a classical computation and we make two backups of the state of the computation at any time. Then we can use this to test whether one of these states has been corrupted by majority voting. But we’ve learned that we can do exactly the same thing for quantum computers: we can detect if the quantum state of one of our copies has been corrupted by encoding into a quantum computer. Now we need to use more than three qubits per bit, but still, this doesn’t seem like such a big deal (from a theorist perspective \ud83d\ude09 ) Now I’d also like to say that I don’t think this is even the way classical computers protect themselves versus malicious software.
\nSo what about attacking the “quantum software?” Well in a standard circuit model of quantum computation, the software is just a list of classical expressions. There is nothing quantum about the data describing a quantum computing program. So it seems that there can’t be any difference here between the quantum and classical world.
\nOh well, I really should get a copy of the New Scientist and figure out if any of this rambling has anything to do with the article (on a similar note, I don’t understand the second part of the post<\/a> at Fact and Fiction. I just don’t see the relevance of copying in a fixed basis: this is something which we almost always avoid in quantum computing because it destroys the coherence properties of the subsystem being so copied.)<\/p>\n","protected":false},"excerpt":{"rendered":"

Over at Fact and Fiction there is an interesting post about an article in New Scientist called Attack of the Quantum Worms. Having not read the article, I thought I’d be an idiot and comment on what one could possibly mean by the statement that quantum computers are more susceptible to malicious attacks. I’m an … <\/p>\n

Continue reading “Superpositions of Worms Going In and Out”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[20,63],"tags":[],"class_list":["post-1114","post","type-post","status-publish","format-standard","hentry","category-computer-science","category-quantum"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/posts\/1114","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/comments?post=1114"}],"version-history":[{"count":0,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/posts\/1114\/revisions"}],"wp:attachment":[{"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/media?parent=1114"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/categories?post=1114"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/tags?post=1114"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}