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<p class="MsoNormal">No love from Akamai for this: it seems to be done for completionist reasons and it seems risky.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">"paul.dale@oracle.com" <paul.dale@oracle.com><br>
<b>Date: </b>Tuesday, April 9, 2019 at 8:07 PM<br>
<b>To: </b>"fips-sponsors@openssl.org" <fips-sponsors@openssl.org><br>
<b>Cc: </b>"openssl-project@openssl.org" <openssl-project@openssl.org><br>
<b>Subject: </b>SP 800-90C 10.1.2<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Do any of the FIPS sponsors or OpenSSL project people think that SP 800-90C section 10.1.2 “<b>Accessing a Source DRBG with Prediction Resistance to Obtain any Security Strength</b>” is worthwhile including in the code base?<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">The main use is to allow a stronger DRBG to be seeded from a weaker one. For example: seeding AES-CTR-256-DRBG from AES-CTR-128-DRBG. The reasons in favour don’t seem very compelling:<o:p></o:p></p>
<ul style="margin-top:0in" type="disc">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo2">There are some obscure use cases for which there is a fairly easy work around (use stronger DRBGs everywhere).
<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo2">A low quality hardware source could be used for higher strength applications.<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo2">It would also provide some benefit for poorly set up DRBG chains.<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo2">It can be used to construct randomness of any strength but I’m not aware of a current method to compress this down to high quality entropy that is directly usable (i.e. preserves the
strength). <o:p></o:p></li></ul>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">The PR is done (#8660 <a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_openssl_openssl_pull_8660&d=DwMFAg&c=96ZbZZcaMF4w0F4jpN6LZg&r=4LM0GbR0h9Fvx86FtsKI-w&m=7y8i8f_jFNGUJCaPCDSdkHqGsI_jO52jpnghkgmKyy0&s=56TxKBgAh-dg3Z-02GgoT6B1_ZYQ9dHMblLe-d8qS3I&e=">
https://github.com/openssl/openssl/pull/8660</a>) but I’ve closed it since it seems unloved. If anyone here does think that that would beneficial, say something as justification or it is gone.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal"><i><span style="mso-fareast-language:EN-AU"> </span></i><o:p></o:p></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-AU">Pauli</span><o:p></o:p></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-AU">-- </span><o:p></o:p></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-AU">Oracle</span><o:p></o:p></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-AU">Dr Paul Dale | Cryptographer | Network Security & Encryption
</span><o:p></o:p></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-AU">Phone +61 7 3031 7217</span><o:p></o:p></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-AU">Oracle Australia</span><o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
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