{"id":12955,"date":"2021-11-30T19:30:53","date_gmt":"2021-12-01T00:30:53","guid":{"rendered":"https:\/\/carleton.ca\/scs\/?page_id=12955"},"modified":"2026-06-02T14:59:25","modified_gmt":"2026-06-02T18:59:25","slug":"tr-97-16-some-timestamping-protocol-failures","status":"publish","type":"page","link":"https:\/\/carleton.ca\/scs\/research\/scs-technical-reports\/technical-reports-1997\/tr-97-16-some-timestamping-protocol-failures\/","title":{"rendered":"TR-97-16: Some Timestamping Protocol Failures"},"content":{"rendered":"\n<section class=\"w-screen px-6 cu-section cu-section--white ml-offset-center md:px-8 lg:px-14\">\n    <div class=\"space-y-6 cu-max-w-child-5xl  md:space-y-10 cu-prose-first-last\">\n\n            <div class=\"cu-textmedia flex flex-col lg:flex-row mx-auto gap-6 md:gap-10 my-6 md:my-12 first:mt-0 max-w-5xl\">\n        <div class=\"justify-start cu-textmedia-content cu-prose-first-last\" style=\"flex: 0 0 100%;\">\n            <header class=\"font-light prose-xl cu-pageheader md:prose-2xl cu-component-updated cu-prose-first-last\">\n                                    <h1 class=\"cu-prose-first-last font-semibold !mt-2 mb-4 md:mb-6 relative after:absolute after:h-px after:bottom-0 after:bg-cu-red after:left-px text-3xl md:text-4xl lg:text-5xl lg:leading-[3.5rem] pb-5 after:w-10 text-cu-black-700 not-prose\">\n                        TR-97-16: Some Timestamping Protocol Failures\n                    <\/h1>\n                \n                                \n                            <\/header>\n\n                    <\/div>\n\n            <\/div>\n\n    <\/div>\n<\/section>\n\n<p>Carleton University<br>\n<a href=\"https:\/\/carleton.ca\/scs\/research\/scs-technical-reports\/technical-reports-1997\/\">Technical Report<\/a> TR-97-16<br>\nAugust 1997<\/p>\n\n\n\n<h2 id=\"tr-97-16-some-timestamping-protocol-failures\" class=\"wp-block-heading tr_t1\">TR-97-16: Some Timestamping Protocol Failures<\/h2>\n\n\n\n<div class=\"tr_t3\">\n<div class=\"tr_t3\">\n<div class=\"tr_t3\">\n<div class=\"tr_t3\">\n<div class=\"tr_t3\">\n<div class=\"tr_t3\">\n<div class=\"tr_t3\">\n<div class=\"tr_t3\">Mike Just<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div>\n<h3>Abstract<\/h3>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<p>Protocol failures are presented for two timestamping schemes. These failures emphasize the importance and difficulty of implementing a secure protocol even though there exist secure underlying algorithms, as well as the importance of clearly defining the goals for a protocol. For the scheme of Benaloh and de Mare (Eurocrypt &#8217;93), it is shown that although an indication of time can be included during the computation of the timestamp, the verification of the timestamp does not allow for the recovery of this temporal measure. For the scheme of Haber and Stornetta (Journal of Cryptology &#8217;91), we demonstrate how a collusion attack between a single user and a timestamping service allows for the backdating of timestamps. This attack is successful despite the claim that the timestamping service need not be trusted. For each of these schemes, we discuss methods for improvement.<\/p>\n\n\n\n<p><a href=\"https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/TR-97-16.pdf\">TR-97-16.pdf<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Carleton University Technical Report TR-97-16 August 1997 TR-97-16: Some Timestamping Protocol Failures Mike Just Abstract Protocol failures are presented for two timestamping schemes. These failures emphasize the importance and difficulty of implementing a secure protocol even though there exist secure underlying algorithms, as well as the importance of clearly defining the goals for a protocol. [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":12157,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_cu_dining_location_slug":"","footnotes":"","_links_to":"","_links_to_target":""},"cu_page_type":[],"class_list":["post-12955","page","type-page","status-publish","hentry"],"acf":{"cu_post_thumbnail":false},"_links":{"self":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/12955","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/comments?post=12955"}],"version-history":[{"count":1,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/12955\/revisions"}],"predecessor-version":[{"id":12956,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/12955\/revisions\/12956"}],"up":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/12157"}],"wp:attachment":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/media?parent=12955"}],"wp:term":[{"taxonomy":"cu_page_type","embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/cu_page_type?post=12955"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}