CINXE.COM
New Techniques for Analyzing Fully Secure Protocols: A Case Study of Solitary Output Secure Computation
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"> <link href="/css/dist/css/bootstrap.min.css" rel="stylesheet"> <title>New Techniques for Analyzing Fully Secure Protocols: A Case Study of Solitary Output Secure Computation</title> <link rel="stylesheet" href="/css/eprint.css?v=10"> <link rel="shortcut icon" href="/favicon.ico" type="image/x-icon" /> <link rel="apple-touch-icon" href="/img/apple-touch-icon-180x180.png" /> <style> a.toggle-open:after { content:' -'; font-weight: 800; } a.toggle-closed:after { content: " ›"; font-weight: 800; } .paper-abstract { white-space: pre-wrap; } #metadata dt { margin-top: 1rem; } #metadata dt + dd { /* gap between dt and first dd */ margin-top: .75rem; } #metadata dd { margin-left: 2rem; } #metadata dd.keywords { padding-bottom: .5rem; } span.authorName { margin-top: .5rem; font-style: italic; } </style> <script> MathJax = { tex: { inlineMath: [['$', '$'], ['\\(', '\\)']], displayMath: [ ['$$','$$'], ["\\[","\\]"] ], processEnvironments: false }, loader: { load: [ "ui/safe", "ui/lazy", ], }, options: { safeOptions: { allow: { URLs: "none", classes: "safe", cssIDs: "safe", styles: "safe", }, }, } }; </script> <script id="MathJax-script" async src="/js/mathjax/tex-chtml.js"></script> <meta name="citation_title" content="New Techniques for Analyzing Fully Secure Protocols: A Case Study of Solitary Output Secure Computation"> <meta name="citation_author" content="Bar Alon"> <meta name="citation_author" content="Benjamin Saldman"> <meta name="citation_author" content="Eran Omri"> <meta name="citation_journal_title" content="Cryptology ePrint Archive"> <meta name="citation_publication_date" content="2025"> <meta name="citation_pdf_url" content="https://eprint.iacr.org/2025/522.pdf"> <meta property="og:image" content="https://eprint.iacr.org/img/iacrlogo.png"/> <meta property="og:image:alt" content="IACR logo"/> <meta property="og:url" content="https://eprint.iacr.org/2025/522"> <meta property="og:site_name" content="IACR Cryptology ePrint Archive" /> <meta property="og:type" content="article" /> <meta property="og:title" content="New Techniques for Analyzing Fully Secure Protocols: A Case Study of Solitary Output Secure Computation" /> <meta property="og:description" content="Solitary output secure computation allows a set of mutually distrustful parties to compute a function of their inputs such that only a designated party obtains the output. Such computations should satisfy various security properties such as correctness, privacy, independence of inputs, and even guaranteed output delivery. We are interested in full security, which captures all of these properties. Solitary output secure computation has been the study of many papers in recent years, as it captures many real-world scenarios. A systematic study of fully secure solitary output computation was initiated by Halevi et al. [TCC 2019]. They showed several positive and negative results, however, they did not characterize what functions can be computed with full security. Alon et al. [EUROCRYPT 2024] considered the special, yet important case, of three parties with Boolean output, where the output-receiving party has no input. They completely characterized the set of such functionalities that can be computed with full security. Interestingly, they also showed a possible connection with the seemingly unrelated notion of fairness, where either all parties obtain the output or none of them do. We continue this line of investigation and study the set of three-party solitary output Boolean functionalities where all parties hold private inputs. Our main contribution is defining and analyzing a family of ``special-round'' protocols, which generalizes the set of previously proposed protocols. Our techniques allow us to identify which special-round protocols securely compute a given functionality (if such exists). Interestingly, our analysis can also be applied in the two-party setting (where fairness is an issue). Thus, we believe that our techniques may prove useful in additional settings and deepen our understanding of the connections between the various settings." /> <meta property="article:section" content="PROTOCOLS" /> <meta property="article:modified_time" content="2025-03-19T21:21:35+00:00" /> <meta property="article:published_time" content="2025-03-19T21:21:35+00:00" /> <meta property="article:tag" content="Solitary output" /> <meta property="article:tag" content="full security" /> <meta property="article:tag" content="impossibility results" /> </head> <body> <noscript> <h1 class="text-center">What a lovely hat</h1> <h4 class="text-center">Is it made out of <a href="https://iacr.org/tinfoil.html">tin foil</a>?</h4> </noscript> <div class="fixed-top" id="topNavbar"> <nav class="navbar navbar-custom navbar-expand-lg"> <div class="container px-0 justify-content-between justify-content-lg-evenly"> <div class="order-0 align-items-center d-flex"> <button class="navbar-toggler btnNoOutline" type="button" data-bs-toggle="collapse" data-bs-target="#navbarContent" aria-controls="navbarContent" aria-expanded="false"> <span class="icon-bar top-bar"></span> <span class="icon-bar middle-bar"></span> <span class="icon-bar bottom-bar"></span> </button> <a class="d-none me-5 d-lg-inline" href="https://iacr.org/"><img class="iacrlogo" src="/img/iacrlogo_small.png" alt="IACR Logo" style="max-width:6rem;"></a> </div> <a class="ePrintname order-1" href="/"> <span class="longNavName">Cryptology ePrint Archive</span> </a> <div class="collapse navbar-collapse order-3" id="navbarContent"> <ul class="navbar-nav me-auto ms-2 mb-2 mb-lg-0 justify-content-end w-100"> <li class="ps-md-3 nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false"> Papers </a> <ul class="dropdown-menu me-3" aria-labelledby="navbarDropdown"> <span class="text-dark mx-3" style="white-space:nowrap;">Updates from the last:</span> <li><a class="dropdown-item ps-custom" href="/days/7">7 days</a></li> <li><a class="dropdown-item ps-custom" href="/days/31">31 days</a></li> <li><a class="dropdown-item ps-custom" href="/days/183">6 months</a></li> <li><a class="dropdown-item ps-custom" href="/days/365">365 days</a></li> <li><hr class="dropdown-divider"></li> <li><a class="dropdown-item" href="/byyear">Listing by year</a></li> <li><a class="dropdown-item" href="/complete">All papers</a></li> <li><a class="dropdown-item" href="/complete/compact">Compact view</a></li> <li><a class="dropdown-item" href="https://www.iacr.org/news/subscribe">Subscribe</a></li> <li><hr class="dropdown-divider"></li> <li><a class="dropdown-item" href="/citation.html">How to cite</a></li> <li><hr class="dropdown-divider"></li> <li><a class="dropdown-item" href="/rss">Harvesting metadata</a></li> </ul> </li> <li class="ps-md-3 nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="submissionsDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false"> Submissions </a> <ul class="dropdown-menu me-3" aria-labelledby="submissionsDropdown"> <li><a class="dropdown-item" href="/submit">Submit a paper</a></li> <li><a class="dropdown-item" href="/revise">Revise or withdraw a paper</a></li> <li><a class="dropdown-item" href="/operations.html">Acceptance and publishing conditions</a></li> </ul> </li> <li class="ps-md-3 nav-item dropdown"> <a class="nav-link dropdown-toggle" href="#" id="aboutDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false"> About </a> <ul class="dropdown-menu me-3" aria-labelledby="aboutDropdown"> <li><a class="dropdown-item" href="/about.html">Goals and history</a></li> <li><a class="dropdown-item" href="/news.html">News</a></li> <li><a class="dropdown-item" href="/stats">Statistics</a></li> <li><a class="dropdown-item" href="/contact.html">Contact</a></li> </ul> </li> </ul> </div> <div class="dropdown ps-md-2 text-right order-2 order-lg-last"> <button class="btn btnNoOutline" type="button" id="dropdownMenuButton1" data-bs-toggle="dropdown" aria-expanded="false"> <img src="/img/search.svg" class="searchIcon" alt="Search Button"/> </button> <div id="searchDd" class="dropdown-menu dropdown-menu-end p-0" aria-labelledby="dropdownMenuButton1"> <form action="/search" method="GET"> <div class="input-group"> <input id="searchbox" name="q" type="search" class="form-control" autocomplete="off"> <button class="btn btn-secondary border input-group-append ml-2"> Search </button> </div> </form> <div class="ms-2 p-1 d-none"><a href="/search">Advanced search</a></div> </div> </div> </div> </nav> </div> <main id="eprintContent" class="container px-3 py-4 p-md-4"> <div class="row mt-4"> <div class="col-md-7 col-lg-8 pe-md-5"> <h4>Paper 2025/522</h4> <h3 class="mb-3">New Techniques for Analyzing Fully Secure Protocols: A Case Study of Solitary Output Secure Computation</h3> <div class="author"><span class="authorName">Bar Alon</span><a class="ms-1" target="_blank" href="https://orcid.org/0000-0002-8392-0245"><img class="align-baseline orcidIcon" src="/img/orcid.svg"></a><span class="affiliation">, Georgetown University</span></div> <div class="author"><span class="authorName">Benjamin Saldman</span><a class="ms-1" target="_blank" href="https://orcid.org/0009-0009-0357-8848"><img class="align-baseline orcidIcon" src="/img/orcid.svg"></a><span class="affiliation">, Ariel University</span></div> <div class="author"><span class="authorName">Eran Omri</span><a class="ms-1" target="_blank" href="https://orcid.org/0000-0001-8928-0587"><img class="align-baseline orcidIcon" src="/img/orcid.svg"></a><span class="affiliation">, Ariel University</span></div> <h5 class="mt-3">Abstract</h5> <p style="white-space: pre-wrap;">Solitary output secure computation allows a set of mutually distrustful parties to compute a function of their inputs such that only a designated party obtains the output. Such computations should satisfy various security properties such as correctness, privacy, independence of inputs, and even guaranteed output delivery. We are interested in full security, which captures all of these properties. Solitary output secure computation has been the study of many papers in recent years, as it captures many real-world scenarios. A systematic study of fully secure solitary output computation was initiated by Halevi et al. [TCC 2019]. They showed several positive and negative results, however, they did not characterize what functions can be computed with full security. Alon et al. [EUROCRYPT 2024] considered the special, yet important case, of three parties with Boolean output, where the output-receiving party has no input. They completely characterized the set of such functionalities that can be computed with full security. Interestingly, they also showed a possible connection with the seemingly unrelated notion of fairness, where either all parties obtain the output or none of them do. We continue this line of investigation and study the set of three-party solitary output Boolean functionalities where all parties hold private inputs. Our main contribution is defining and analyzing a family of ``special-round'' protocols, which generalizes the set of previously proposed protocols. Our techniques allow us to identify which special-round protocols securely compute a given functionality (if such exists). Interestingly, our analysis can also be applied in the two-party setting (where fairness is an issue). Thus, we believe that our techniques may prove useful in additional settings and deepen our understanding of the connections between the various settings.</p> </div> <div id="metadata" class="col-md-5 col-lg-4 ps-md-5 mt-4 mt-md-0"> <h5>Metadata</h5> <dl> <dt> Available format(s) </dt> <dd> <a class="btn btn-sm btn-outline-dark" href="/2025/522.pdf"> <img class="icon" src="/img/file-pdf.svg">PDF</a> </dd> <dt>Category</dt> <dd><a href="/search?category=PROTOCOLS"><small class="badge category category-PROTOCOLS">Cryptographic protocols</small></a></dd> <dt>Publication info</dt> <dd>Preprint. </dd> <dt>Keywords</dt> <dd class="keywords"><a href="/search?q=Solitary%20output" class="me-2 badge bg-secondary keyword">Solitary output</a><a href="/search?q=full%20security" class="me-2 badge bg-secondary keyword">full security</a><a href="/search?q=impossibility%20results" class="me-2 badge bg-secondary keyword">impossibility results</a></dd> <dt>Contact author(s)</dt> <dd><span class="font-monospace"> alonbar08<span class="obfuscate"> @ </span>gmail com<br>binyaminsaldman<span class="obfuscate"> @ </span>gmail com<br>omrier<span class="obfuscate"> @ </span>ariel ac il </span> </dd> <dt>History</dt> <dd>2025-03-21: approved</dd> <dd>2025-03-19: received</dd> <dd><a rel="nofollow" href="/archive/versions/2025/522">See all versions</a></dd> <dt>Short URL</dt> <dd><a href="https://ia.cr/2025/522">https://ia.cr/2025/522</a></dd> <dt>License</dt> <dd><a rel="license" target="_blank" href="https://creativecommons.org/licenses/by/4.0/"> <img class="licenseImg" src="/img/license/CC_BY.svg" alt="Creative Commons Attribution" title="Creative Commons Attribution"><br> <small>CC BY</small> </a> </dd> </dl> </div> </div> <p class="mt-4"><strong>BibTeX</strong> <button id="bibcopy" class="ms-2 btn btn-sm btn-outline-dark" aria-label="Copy to clipboard" onclick="copyBibtex()"> <img src="/img/copy-outline.svg" class="icon">Copy to clipboard</button></p> <pre id="bibtex"> @misc{cryptoeprint:2025/522, author = {Bar Alon and Benjamin Saldman and Eran Omri}, title = {New Techniques for Analyzing Fully Secure Protocols: A Case Study of Solitary Output Secure Computation}, howpublished = {Cryptology {ePrint} Archive, Paper 2025/522}, year = {2025}, url = {https://eprint.iacr.org/2025/522} } </pre> <script> var bibcopy; function triggerTooltip() { console.log('setting tooltip'); } window.onload = triggerTooltip; function copyBibtex() { let range = document.createRange(); range.selectNode(document.getElementById('bibtex')); window.getSelection().removeAllRanges(); window.getSelection().addRange(range); document.execCommand('copy'); window.getSelection().removeAllRanges(); let bibcopy = document.getElementById('bibcopy'); let copyTooltip = new bootstrap.Tooltip(bibcopy, {trigger: 'manual', title: 'Copied!'}); copyTooltip.show(); setTimeout(function() { copyTooltip.dispose(); }, 2000); } </script> </main> <div class="container-fluid mt-auto" id="eprintFooter"> <a href="https://iacr.org/"> <img id="iacrlogo" src="/img/iacrlogo_small.png" class="img-fluid d-block mx-auto" alt="IACR Logo"> </a> <div class="colorDiv"></div> <div class="alert alert-success w-75 mx-auto"> Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content. </div> </div> <script src="/css/bootstrap/js/bootstrap.bundle.min.js"></script> <script> var topNavbar = document.getElementById('topNavbar'); if (topNavbar) { document.addEventListener('scroll', function(e) { if (window.scrollY > 100) { topNavbar.classList.add('scrolled'); } else { topNavbar.classList.remove('scrolled'); } }) } </script> </body> </html>