Anybody can generate a DSA key and use it, there's no restriction.<div><br><div>It's different from RSA in several ways:</div><div> - can be used for signature only (to sign a DH key which will be used to agree on a key for encipherment)</div>
<div> - you separate domain parameters generation and key generation; domain parameters set the security level of the keys and can be shared between any number of unrelated users, DSA key generation is way faster than RSA</div>
<div> - signing/verifying cost ratio is reversed (faster signatures than verifications); this could have been an advantage against basic TLS DoS tools such as THC-SSL-DOS, or not (it depends on the negotiated ciphersuite)</div>
<div> - signing is extremely fault intolerant; a secret random is generated for each signature, if a random is reused the private key can be recovered; if this random can be predicted (even a few bits) part of the private key can be recovered; if the random is revealed the private key can be recovered; this intolerance is shared with ECDSA</div>
<div> - limitations to 1024 bits come from DSS (the FIPS186 standard), which specifies acceptable parameters for DSA, and the first edition allowed for 1024 bits max with SHA1 hash, which has a security level equivalent to a 1024 bits RSA (80 bits of security)</div>
<div><br></div><div>I don't see any value added in using DSA2048/3072. It's not as fast as pure RSA for a full TLS handshake if you're concerned with performance, and if you want to keep forward-secrecy, RSA+(EC)DHE works today with probably similar performance. It's also not compatible with RC4-* ciphersuites, which shouldn't be a problem in an ideal world where BEAST doesn't apply.</div>
<div><br></div><div>I don't have any problem allowing its use, either.</div><div><br></div><div>Haven't check the BR in the past few days, is ECDSA allowed?</div><div><br><div class="gmail_quote">2013/3/8 <a href="mailto:kirk_hall@trendmicro.com">kirk_hall@trendmicro.com</a> <span dir="ltr"><<a href="mailto:kirk_hall@trendmicro.com" target="_blank">kirk_hall@trendmicro.com</a>></span><br>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Rick, I don’t know much about DSA (other than it’s a different algorithm).
<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="http://en.wikipedia.org/wiki/Digital_Signature_Algorithm" target="_blank">http://en.wikipedia.org/wiki/Digital_Signature_Algorithm</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Does it present any issues that are different from RSA algorithm certs?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Same authentication processes and security considerations?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Can only government agencies obtain these certs, or can any user?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:public-bounces@cabforum.org" target="_blank">public-bounces@cabforum.org</a> [mailto:<a href="mailto:public-bounces@cabforum.org" target="_blank">public-bounces@cabforum.org</a>]
<b>On Behalf Of </b>Rick Andrews<br>
<b>Sent:</b> Friday, March 08, 2013 11:40 AM<br>
<b>To:</b> Ryan Hurst; 'CABFPub'; Erwann Abalea<br>
<b>Subject:</b> Re: [cabfpub] Proposal to add DSA 2048<u></u><u></u></span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">We’re working with Stanford and CMU to do performance testing, but it will be a few weeks before we have results.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Regardless of performance, does anyone have any problem with explicitly adding DSA 2048 to the BRs?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">-Rick<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> <a href="mailto:public-bounces@cabforum.org" target="_blank">public-bounces@cabforum.org</a> [mailto:<a href="mailto:public-bounces@cabforum.org" target="_blank">public-bounces@cabforum.org</a>]
<b>On Behalf Of </b>Ryan Hurst<br>
<b>Sent:</b> Thursday, March 07, 2013 7:29 PM<br>
<b>To:</b> Rick Andrews; 'CABFPub'; Erwann Abalea<br>
<b>Subject:</b> Re: [cabfpub] Proposal to add DSA 2048<u></u><u></u></span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I just remembered a post I did on this topic:
<a href="http://unmitigatedrisk.com/?p=50" target="_blank">http://unmitigatedrisk.com/?p=50</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I just reread it and ran across Erwann’s comment about the performance implications of DH and its use in SSL. This also makes me wonder if anyone has done performance
benchmarking of DSA 2048 relative to RSA looking at the DH overhead and DSA costs as a whole – basically does it really provide you any value?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Ryan<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Ryan Hurst [mailto:<a href="mailto:ryan.hurst@globalsign.com" target="_blank">ryan.hurst@globalsign.com</a>]
<br>
<b>Sent:</b> Thursday, March 07, 2013 7:25 PM<br>
<b>To:</b> 'Rick Andrews'; 'CABFPub (<a href="mailto:public@cabforum.org" target="_blank">public@cabforum.org</a>)'<br>
<b>Subject:</b> RE: [cabfpub] Proposal to add DSA 2048<u></u><u></u></span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">The performance properties of DSA are great relative to RSA for servers but major clients (as far as I know) do not support DSA keys larger than 1024, I know
this is the case for anything that relies on CryptoAPI in Windows. Out of curiosity are there major browsers that can work with such keys or are your scenarios limited to custom applications?<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Ryan<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">
<a href="mailto:public-bounces@cabforum.org" target="_blank">public-bounces@cabforum.org</a> [<a href="mailto:public-bounces@cabforum.org" target="_blank">mailto:public-bounces@cabforum.org</a>]
<b>On Behalf Of </b>Rick Andrews<br>
<b>Sent:</b> Thursday, March 07, 2013 4:23 PM<br>
<b>To:</b> CABFPub (<a href="mailto:public@cabforum.org" target="_blank">public@cabforum.org</a>)<br>
<b>Subject:</b> [cabfpub] Proposal to add DSA 2048<u></u><u></u></span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">Symantec has begun offering SSL certificates with DSA 2048-bit keys. Since DSA is not mentioned in the Baseline Requirements or EV Guidelines, I’d like to explicitly add
DSA 2048 in BR Appendix A as the minimum DSA key size.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> <u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">If there are no objections, I’ll draft a ballot and seek endorsers.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> <u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">-Rick
<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> <u></u><u></u></span></p>
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