{"id":2385,"date":"2025-01-23T17:14:14","date_gmt":"2025-01-23T15:14:14","guid":{"rendered":"https:\/\/webs.uab.cat\/giq\/?post_type=seminar&#038;p=2385"},"modified":"2025-03-18T18:11:59","modified_gmt":"2025-03-18T16:11:59","slug":"quantum-position-verification-loss-and-entanglement","status":"publish","type":"seminar","link":"https:\/\/webs.uab.cat\/giq\/seminar\/quantum-position-verification-loss-and-entanglement\/","title":{"rendered":"Quantum position verification: loss and entanglement"},"content":{"rendered":"\n<p><em>In the talk, I will introduce the concept of quantum position verification (QPV), which consists of verifying the location of an untrusted prover using quantum mechanics and special relativity. I will summarize significant results from the literature and present new findings, with special emphasis on how signal loss threatens the security of quantum cryptography when protocols lack loss-tolerance. In QPV, even small loss rates can compromise security!<br>I will analyze the exact loss-tolerance of the QPV protocol based on BB84 states, which becomes insecure if attackers pre-share a single EPR pair. While adding classical information can mitigate this, it requires a transmission rate exceeding 50%, making it impractical over long distances. Finally, I will present a \u00a0result that makes arbitrary photon loss irrelevant to security, and combining it with the BB84-based protocol, offers a promising, implementable solution.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the talk, I will introduce the concept of quantum position verification (QPV), which consists of verifying the location of an untrusted prover using quantum mechanics and special relativity. I will summarize significant results from the literature and present new findings, with special emphasis on how signal loss threatens the security of quantum cryptography when [&hellip;]<\/p>\n","protected":false},"author":2605,"featured_media":0,"template":"","class_list":["post-2385","seminar","type-seminar","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/seminar\/2385","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/seminar"}],"about":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/types\/seminar"}],"author":[{"embeddable":true,"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/users\/2605"}],"wp:attachment":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/media?parent=2385"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}