Good day,<br><br>I agree with Tom that it seems like the questions were definitively not vetted properly.<br><br>The total number of keys needed for asymmetric is simply total number of users multiply by 2<br><br>10 users is 20 keys that would be created overall. <br>
<br>If it was Symmetric then you would use the formula: total number of users X total number of users minus one divided by two. 10 x (10-1)/2 which is 45 keys.<br><br>For the second question: all the services would be provided using Digital Signatures which can only be achieve within asymmetric crypto systems. While creating the digital signature the hashing algorithm would be use.<br>
<br>Take care<br><br>Clement<br><br>
<br><br><div class="gmail_quote">On Tue, Jan 19, 2010 at 16:07, Nimal Gunarathna <span dir="ltr"><<a href="mailto:ng949@yahoo.com">ng949@yahoo.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; font-size: inherit; line-height: inherit; font-size-adjust: inherit; font-stretch: inherit;" valign="top">
Hi Tom,<div><br></div><div>This question puzzles me..</div><div>In an asymmetric system how many keys are required for 10 users to fully<br>communicate?<br><div><br></div><div>Every user has a one private and a one public key. I can send my same public</div>
<div>key to all others. For 10 people, 20 keys are needed.. I am not sure how 110 come from?</div><div>Is this a private com session or just a different comm session with each pair?</div><div><br></div><div>Thanks,</div><div>
<br></div><div>Nimal Gunarathna </div><div><br><div><div><br></div><div><br></div><div>--- On <b>Tue, 1/19/10, <a href="mailto:cisspstudy-request@cccure.org" target="_blank">cisspstudy-request@cccure.org</a> <i><<a href="mailto:cisspstudy-request@cccure.org" target="_blank">cisspstudy-request@cccure.org</a>></i></b> wrote:<br>
<blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: <a href="mailto:cisspstudy-request@cccure.org" target="_blank">cisspstudy-request@cccure.org</a>
<<a href="mailto:cisspstudy-request@cccure.org" target="_blank">cisspstudy-request@cccure.org</a>><br>Subject: cisspstudy Digest, Vol 19, Issue 16<br>To: <a href="mailto:cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a><br>
Date: Tuesday, January 19, 2010, 11:00 AM<br><br><div>Send cisspstudy mailing list submissions to<br> <a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a><br><br>To subscribe or unsubscribe via the World Wide Web, visit<br>
<a href="http://cccure.org/mailman/listinfo/cisspstudy_cccure.org" target="_blank">http://cccure.org/mailman/listinfo/cisspstudy_cccure.org</a><br>or, via email, send a message with subject or body 'help' to<br>
<a href="http://mc/compose?to=cisspstudy-request@cccure.org" target="_blank">cisspstudy-request@cccure.org</a><br><br>You can reach the person managing the list at<br> <a href="http://mc/compose?to=cisspstudy-owner@cccure.org" target="_blank">cisspstudy-owner@cccure.org</a><br>
<br>When replying, please edit your Subject line so it is more specific<br>than "Re: Contents of cisspstudy digest..."<br><br><br>Today's Topics:<br><br> 1. cisspstudy - Cryptography questions (<a href="http://mc/compose?to=twitwicki@hannaford.com" target="_blank">twitwicki@hannaford.com</a>)<br>
2. Re: New to CISSP Cert (Mark Price)<br> 3. Re: New to CISSP Cert (jack wang)<br> 4. Re: New to CISSP Cert (Jeronimo Zucco)<br><br><br>----------------------------------------------------------------------<br><br>
Message: 1<br>Date: Mon, 18 Jan 2010 14:48:26 -0500<br>From: <a href="http://mc/compose?to=twitwicki@hannaford.com" target="_blank">twitwicki@hannaford.com</a><br>To: <a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a><br>
Subject: [Cisspstudy] cisspstudy - Cryptography questions<br>Message-ID:<br> <<a href="http://mc/compose?to=OF8F407D94.BBDB76DE-ON852576AF.006B4314-852576AF.006CCD97@hannaford.com" target="_blank">OF8F407D94.BBDB76DE-ON852576AF.006B4314-852576AF.006CCD97@hannaford.com</a>><br>
<br>Content-Type: text/plain; charset=US-ASCII<br><br><br><br>Hello all,<br> I'd like your thoughts on these questions from Michael Gregg's CISSP<br>Practice questions:<br><br>In an asymmetric system how many keys are required for 10 users to fully<br>
communicate?<br><br>A. 10<br>B. 20<br>C. 45<br>D 110<br><br>The answer states D. 110 - "Each user would have his private, phus his<br>public key, plus each of the nine other public keys"<br>Shouldn't the answer be B.
20 because the public keys is only couned once<br>for each private/public pair? This also seems consistent with the formula<br>for symmetric keys: N(N-1)/2 where N is the number of users needing to<br>communicate. In this case the secret key is only counted once even if it's<br>
shared between users.<br><br><br>Here's another question that has me puzzled:<br><br>Which cryptographic system can be used for integrity, authenticity and<br>non-repudiation?<br><br>A. Asymmetric encryption<br>B. Symmetric encryption<br>
C. Hashing<br>D. None of the above<br><br>The answers states A. Asymmetric. Shouldn't the answer be D. None of the<br>above because Hashing is needed for integrity?<br><br>Your thoughts will be much appreciated.<br><br>
<br>Tom Witwicki, CIPP<br>Director, Information Security<br>Hannaford Bros. Co.<br>207-885-2073<br><br>Join me on Linkedin!<br><a href="http://www.linkedin.com/in/tomwitwicki" target="_blank">http://www.linkedin.com/in/tomwitwicki</a><br>
<br><br><br><br><br><br><br>------------------------------<br><br>Message: 2<br>Date: Mon, 18 Jan 2010 21:47:45 +0000<br>From: "Mark Price" <<a href="http://mc/compose?to=prinext@gmail.com" target="_blank">prinext@gmail.com</a>><br>
To: "The CISSP Study Mailing list" <<a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a>><br>Subject: Re: [Cisspstudy] New to CISSP Cert<br>Message-ID:<br> <<a href="http://mc/compose?to=1180962559-1263851266-cardhu_decombobulator_blackberry.rim.net-147941822-@bda153.bisx.prod.on.blackberry" target="_blank">1180962559-1263851266-cardhu_decombobulator_blackberry.rim.net-147941822-@bda153.bisx.prod.on.blackberry</a>><br>
<br>Content-Type:
text/plain<br><br>I have heard each edition is an update of the previous plus more of the latest technology and or standards. <br>I have the 4th and the DVD set, they plus <a href="http://cccure.org" target="_blank">cccure.org</a> worked for me.<br>
V/r,<br><br>Mark Price<br>PRINEXT<br>c:240-743-7654<br><a href="http://mc/compose?to=mprice@prinext.com" target="_blank">mprice@prinext.com</a><br><a href="http://www.prinext.com" target="_blank">www.prinext.com</a><br><br>
-----Original Message-----<br>From: Cert Prep <<a href="http://mc/compose?to=bugtraq.mailbox@gmail.com" target="_blank">bugtraq.mailbox@gmail.com</a>><br>Date: Mon, 18 Jan 2010 13:22:40 <br>To: The CISSP Study Mailing list<<a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a>><br>
Subject: Re: [Cisspstudy] New to CISSP Cert<br><br>Thanks Jeronimo. I will listen to it.<br><br>I have Shon Harris Second Edition which I bought many years back. I<br>have heard that 5th edition is about to
come. Is it ok to prepare from<br>second edition until 5th edition is out? Does anybody know the<br>differences between 2nd and 4th? I am sure there will be many but are<br>those drastic to the extent that I will have to revise the stuff,<br>
which I have already gone through using second edition, from 5th<br>edition once it is published?<br><br>Any help would be appreciated.<br><br>Thanks.<br>Adam<br><br>On Mon, Jan 18, 2010 at 12:51 PM, Jeronimo Zucco <<a href="http://mc/compose?to=jczucco@gmail.com" target="_blank">jczucco@gmail.com</a>> wrote:<br>
> 2010/1/18 Cert Prep <<a href="http://mc/compose?to=bugtraq.mailbox@gmail.com" target="_blank">bugtraq.mailbox@gmail.com</a>>:<br>>> Hi Folks,<br>>><br>>> I am planning to prepare for CISSP Cert and would like to know which<br>
>> book or material is best for the preparations.<br>><br>><br>> <a href="http://www.cccure.org/flash/intro/player.html" target="_blank">http://www.cccure.org/flash/intro/player.html</a><br>><br>><br>
><br>> --<br>> Jeronimo Zucco<br>> <a href="http://jczucco.blogspot.com" target="_blank">http://jczucco.blogspot.com</a><br>><br>> _______________________________________________<br>> cisspstudy mailing list<br>
> <a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a><br>> <a href="http://cccure.org/mailman/listinfo/cisspstudy_cccure.org" target="_blank">http://cccure.org/mailman/listinfo/cisspstudy_cccure.org</a><br>
><br><br>_______________________________________________<br>cisspstudy mailing list<br><a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a><br><a href="http://cccure.org/mailman/listinfo/cisspstudy_cccure.org" target="_blank">http://cccure.org/mailman/listinfo/cisspstudy_cccure.org</a><br>
<br>------------------------------<br><br>Message: 3<br>Date: Tue, 19 Jan 2010 20:05:00 +0800<br>From: jack wang <<a href="http://mc/compose?to=windjie@gmail.com" target="_blank">windjie@gmail.com</a>><br>To: The CISSP Study Mailing list <<a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a>><br>
Subject: Re: [Cisspstudy] New to CISSP Cert<br>Message-ID:<br> <<a href="http://mc/compose?to=3c43566f1001190405t2bfd204as4a953dd160a5b92b@mail.gmail.com" target="_blank">3c43566f1001190405t2bfd204as4a953dd160a5b92b@mail.gmail.com</a>><br>
Content-Type: text/plain; charset="iso-8859-1"<br><br> Shon Harris Second Edition,plus <a href="http://www.cccure.org" target="_blank">www.cccure.org</a>,they are enough<br>-------------- next part --------------<br>
An HTML attachment was
scrubbed...<br>URL: <<a href="http://cccure.org/pipermail/cisspstudy_cccure.org/attachments/20100119/0d0b7b8f/attachment-0001.html" target="_blank">http://cccure.org/pipermail/cisspstudy_cccure.org/attachments/20100119/0d0b7b8f/attachment-0001.html</a>><br>
<br>------------------------------<br><br>Message: 4<br>Date: Tue, 19 Jan 2010 10:34:19 -0200<br>From: Jeronimo Zucco <<a href="http://mc/compose?to=jczucco@gmail.com" target="_blank">jczucco@gmail.com</a>><br>To: The CISSP Study Mailing list <<a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a>><br>
Subject: Re: [Cisspstudy] New to CISSP Cert<br>Message-ID:<br> <<a href="http://mc/compose?to=2d6b298c1001190434i6f1eb72ct1157b63b80fe9301@mail.gmail.com" target="_blank">2d6b298c1001190434i6f1eb72ct1157b63b80fe9301@mail.gmail.com</a>><br>
Content-Type: text/plain; charset=ISO-8859-1<br><br>All-in_one edition 5:<br><br><a href="http://www.amazon.com/CISSP-All-One-Guide-Fifth/dp/0071602178/ref=sr_1_2?ie=UTF8&s=books&qid=1263898897&sr=8-2" target="_blank">http://www.amazon.com/CISSP-All-One-Guide-Fifth/dp/0071602178/ref=sr_1_2?ie=UTF8&s=books&qid=1263898897&sr=8-2</a><br>
<br>I always recommend the last edition, because of updates and<br>corretions. Or you can read all erratas for your edition.<br><br>2010/1/19 jack wang <<a href="http://mc/compose?to=windjie@gmail.com" target="_blank">windjie@gmail.com</a>>:<br>
> ?Shon Harris Second Edition,plus <a href="http://www.cccure.org" target="_blank">www.cccure.org</a>,they are enough<br>><br><br><br>-- <br>Jeronimo Zucco<br><a href="http://jczucco.blogspot.com" target="_blank">http://jczucco.blogspot.com</a><br>
<br><br><br>------------------------------<br><br>_______________________________________________<br>cisspstudy mailing list<br><a href="http://mc/compose?to=cisspstudy@cccure.org" target="_blank">cisspstudy@cccure.org</a><br>
<a href="http://cccure.org/mailman/listinfo/cisspstudy_cccure.org" target="_blank">http://cccure.org/mailman/listinfo/cisspstudy_cccure.org</a><br><br><br>End of cisspstudy Digest, Vol 19, Issue 16<br>******************************************<br>
</div></blockquote></div></div></div></div></td></tr></tbody></table><br>_______________________________________________<br>
cisspstudy mailing list<br>
<a href="mailto:cisspstudy@cccure.org">cisspstudy@cccure.org</a><br>
<a href="http://cccure.org/mailman/listinfo/cisspstudy_cccure.org" target="_blank">http://cccure.org/mailman/listinfo/cisspstudy_cccure.org</a><br>
<br></blockquote></div><br>