{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,6]],"date-time":"2025-12-06T00:36:40Z","timestamp":1764981400728,"version":"3.46.0"},"reference-count":0,"publisher":"Walter de Gruyter GmbH","issue":"2","license":[{"start":{"date-parts":[[2014,1,24]],"date-time":"2014-01-24T00:00:00Z","timestamp":1390521600000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/3.0\/"}],"funder":[{"DOI":"10.13039\/501100000038","name":"NSERC","doi-asserted-by":"crossref","award":["203114-11"],"award-info":[{"award-number":["203114-11"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2014,6,1]]},"abstract":"<jats:title>Abstract.<\/jats:title>\n                  <jats:p>\n                    Proof-of-retrievability schemes have been\na topic of considerable recent interest.\nIn these schemes,\na client\n                    <jats:inline-formula id=\"eq1_w2aab3b7c15b1b6b1aab1c13b1b1Aa\">\n                      <jats:alternatives>\n                        <m:math xmlns:m=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                          <m:mi>\ud835\udda2<\/m:mi>\n                        <\/m:math>\n                        <jats:tex-math>$\\mathsf {C}$<\/jats:tex-math>\n                      <\/jats:alternatives>\n                    <\/jats:inline-formula>\n                    gives a file\n                    <jats:italic>M<\/jats:italic>\n                    to a server\n                    <jats:inline-formula id=\"eq2_w2aab3b7c15b1b6b1aab1c13b1b5Aa\">\n                      <jats:alternatives>\n                        <m:math xmlns:m=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                          <m:mi>\ud835\uddb2<\/m:mi>\n                        <\/m:math>\n                        <jats:tex-math>$\\mathsf {S}$<\/jats:tex-math>\n                      <\/jats:alternatives>\n                    <\/jats:inline-formula>\n                    with the understanding\nthat\n                    <jats:inline-formula id=\"eq3_w2aab3b7c15b1b6b1aab1c13b1b7Aa\">\n                      <jats:alternatives>\n                        <m:math xmlns:m=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                          <m:mi>\ud835\uddb2<\/m:mi>\n                        <\/m:math>\n                        <jats:tex-math>$\\mathsf {S}$<\/jats:tex-math>\n                      <\/jats:alternatives>\n                    <\/jats:inline-formula>\n                    will securely store\n                    <jats:italic>M<\/jats:italic>\n                    .\nA suitable challenge-response protocol is invoked by\n                    <jats:inline-formula id=\"eq4_w2aab3b7c15b1b6b1aab1c13b1c11Aa\">\n                      <jats:alternatives>\n                        <m:math xmlns:m=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                          <m:mi>\ud835\udda2<\/m:mi>\n                        <\/m:math>\n                        <jats:tex-math>$\\mathsf {C}$<\/jats:tex-math>\n                      <\/jats:alternatives>\n                    <\/jats:inline-formula>\n                    in order for\n                    <jats:inline-formula id=\"eq5_w2aab3b7c15b1b6b1aab1c13b1c13Aa\">\n                      <jats:alternatives>\n                        <m:math xmlns:m=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                          <m:mi>\ud835\udda2<\/m:mi>\n                        <\/m:math>\n                        <jats:tex-math>$\\mathsf {C}$<\/jats:tex-math>\n                      <\/jats:alternatives>\n                    <\/jats:inline-formula>\n                    to gain confidence that\n                    <jats:italic>M<\/jats:italic>\n                    is indeed being correctly stored by\n                    <jats:inline-formula id=\"eq6_w2aab3b7c15b1b6b1aab1c13b1c17Aa\">\n                      <jats:alternatives>\n                        <m:math xmlns:m=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                          <m:mi>\ud835\uddb2<\/m:mi>\n                        <\/m:math>\n                        <jats:tex-math>$\\mathsf {S}$<\/jats:tex-math>\n                      <\/jats:alternatives>\n                    <\/jats:inline-formula>\n                    .\nThe definition of proof-of-retrievability schemes is based on the notion of\nan extractor\n                    <jats:inline-formula id=\"eq7_w2aab3b7c15b1b6b1aab1c13b1c19Aa\">\n                      <jats:alternatives>\n                        <m:math xmlns:m=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                          <m:mi>\u2130<\/m:mi>\n                        <\/m:math>\n                        <jats:tex-math>$\\mathcal {E}$<\/jats:tex-math>\n                      <\/jats:alternatives>\n                    <\/jats:inline-formula>\n                    that can recover the file once the\nchallenge-response protocol is executed a sufficient number of times.\nIn this paper, we propose a new type of scheme that we term a\n                    <jats:italic>proof-of-data-observability scheme<\/jats:italic>\n                    .\nOur definition tries to capture the stronger requirement that\n                    <jats:inline-formula id=\"eq8_w2aab3b7c15b1b6b1aab1c13b1c23Aa\">\n                      <jats:alternatives>\n                        <m:math xmlns:m=\"http:\/\/www.w3.org\/1998\/Math\/MathML\">\n                          <m:mi>\ud835\uddb2<\/m:mi>\n                        <\/m:math>\n                        <jats:tex-math>$\\mathsf {S}$<\/jats:tex-math>\n                      <\/jats:alternatives>\n                    <\/jats:inline-formula>\n                    must have\nan actual copy of\n                    <jats:italic>M<\/jats:italic>\n                    in its memory space while it executes the challenge-response protocol.\nWe give some examples of schemes that satisfy this new\nsecurity definition. As well, we analyze the efficiency and security of the protocols we present,\nand we prove some necessary conditions for the existence of these kinds of protocols.\n                  <\/jats:p>","DOI":"10.1515\/jmc-2013-0034","type":"journal-article","created":{"date-parts":[[2014,1,25]],"date-time":"2014-01-25T15:18:31Z","timestamp":1390663111000},"page":"189-207","source":"Crossref","is-referenced-by-count":0,"title":["Is extracting data the same as possessing data?"],"prefix":"10.1515","volume":"8","author":[{"given":"Douglas R.","family":"Stinson","sequence":"first","affiliation":[{"name":"David R. Cheriton School of Computer Science, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada"}]},{"given":"Jalaj","family":"Upadhyay","sequence":"additional","affiliation":[{"name":"David R. Cheriton School of Computer Science, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada"}]}],"member":"374","published-online":{"date-parts":[[2014,1,24]]},"container-title":["Journal of Mathematical Cryptology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/jmc-2013-0034\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/jmc-2013-0034\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,6]],"date-time":"2025-12-06T00:33:22Z","timestamp":1764981202000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.degruyterbrill.com\/document\/doi\/10.1515\/jmc-2013-0034\/html"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,1,24]]},"references-count":0,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2014,1,24]]},"published-print":{"date-parts":[[2014,6,1]]}},"alternative-id":["10.1515\/jmc-2013-0034"],"URL":"https:\/\/doi.org\/10.1515\/jmc-2013-0034","relation":{},"ISSN":["1862-2984","1862-2976"],"issn-type":[{"type":"electronic","value":"1862-2984"},{"type":"print","value":"1862-2976"}],"subject":[],"published":{"date-parts":[[2014,1,24]]}}}