hi kevin (and sc-l),

Sorry for the delay responding to this.  I was skiing yesterday with my son Eli 
and just flew across the country for the SANS summit this morning (leaving 
behind 6 inches of new snow in VA).  Anyway, better late than never.

I'll interleave responses below.

On Thu, 28 Jan 2010 10:34:30 -0500, Gary McGraw wrote:
>> "Cargo Cult Computer Security: Why we need more description and less
>> prescription."  http://www.informit.com/articles/article.aspx?p=1562220

          >On 2/2/10 12:30 PM, "Wall, Kevin" <kevin.w...@qwest.com> wrote:
           > In my 11 years of experience working
>on this SSG, it is very rare that application development teams are
>looking for a _descriptive_ approach. Almost always, they are
>looking for a _prescriptive_ one. They want specific solutions
>to specific problems, not some general formula to an approach that will
          >make them more secure.

Absolutely.  I think as an SSG lead in a particular company environment you 
must have a prescriptive approach but that the approach you develop will be 
better if informed by data from a descriptive model like BSIMM.  (For the 
record, I see SAMM as a prescriptive model that tells you often in great detail 
what your initiative should be doing without knowing one whit about how your 
organization ticks.)   If you read the article carefully, there are two 
paragraphs that together should make this clear.

Here's the first:
"Prescriptive models purport to tell you what you should do.  Promulgators of 
such models say things more like, "the model is chocked full of value 
judgements [sic] about what organizations SHOULD be doing."   That's just 
dandy, as long as any prescriptive model only became prescriptive over time 
based on sufficient observation and testing."

And here's the second:
"Also worthy of mention in this section is the "one size fits all" problem that 
many prescriptive models suffer from.  The fact is, nobody knows your 
organizational culture like you do. A descriptive comparison allows you to 
gather descriptive data and adapt good ideas from others while taking your 
culture into account."

BSIMM is meant to be a tool for the people running and SSG (and for that 
matter, strategizing about a company's software security initiative).  The 
article is really about the differences between BSIMM and SAMM than anything 
else.  It's not really about the difference between BSIMM and ESAPI.  BSIMM and 
things like ESAPI fit together.

>Both are useful and ideally should go together like hand and glove.

Exactly right.

>I suspect that this apparent dichotomy in our perception of the
>usefulness of the prescriptive vs. descriptive approaches is explained
>in part by the different audiences with whom we associate.

Agreed.  See above.   BSIMM is a tool for executives to help build, measure, 
and maintain a software security initiative.

>If our SSG were to hand them something like
>BSIMM, they would come away telling their management that we didn't help
>them at all.

Please do NOT even think about handing the BSIMM to developers as a solution!  
The BSIMM is a yardstick for an initiative, and it's meant for a guy like you.  
The notion is to measure your own initiative and most importantly of all 
compare your initiative to your peers.

>This brings me to my fourth, and likely most controversial point. Despite
>the interesting historical story about Feynman, I question whether BSIMM
>is really "scientific" as the BSIMM community claims. I would contend
>that we are only fooling ourselves if we claim otherwise.

I think this is a valid criticism.  The only thing that makes BSIMM more 
scientific than other methodologies like the Touchoints, SDL, CLASP, or SAMM, 
is that the BSIMM uses real data and real measurement.  However the measurement 
technique is certainly not foolproof.  (Incidentally, I state that view pretty 
clearly in the article...computer science, and other fields with "science" in 
their name are usually not.)

>While I am certainly not privy to the exact method used to arrive at the
>BSIMM data (I have read through the "BSIMM Begin" survey, but have not
>been involved in a full BSIMM assessment), I would contend that the
>process is not repeatable to the necessary degree required by science.

This criticism holds some water, but you are shooting from the hip and it is 
pretty clear that you have not read the BSIMM itself.   That, and the first 
article we wrote about the BSIMM explain our methods pretty clearly. Please 
read those two things and lets continue this line of questioning.

>I challenge [the BSIMM team] to put forth additional information explaining 
>their data collection
>process and in particular, describing how it avoids unintentional bias. (E.g., 
>Are assessment participants choose >at random? By whom?  How do you know you 
>have a representative sample of
>a company? Etc.)

This is pretty clearly explained in the BSIMM itself.

>In my opinion, comparison of observations from two companies is not
>worth the paper that is printed on UNLESS we can extrapolate from
>this data and make accurate predictions based on past findings.

Given the reaction to actual results from the 30 companies who have 
participated so far in the study, I'll respectfully call you out as incorrect 
on that one.  Turns out that most people who run large SSGs and initiatives are 
hungry for comparison with peers (and indeed want to meet and learn from the 
peers).  Experience in the field is bearing out the utility of the BSIMM, and 
the fact that the data we are gathering is supporting the model in important 
ways is no small potatoes either.

>After observing this field for 30+ years (ouch!), I have concluded that we 
>[computer science]
>have not matured into a science because as a discipline we *do NOT
>really want to!*

Some of us do.  Others don't.  But I think a sea change is underway even in our 
little subfield of software security

>... efforts such as BSIMM should be welcomed
>by all.  But is also important for those who prefer _descriptive_ approaches
>like BSIMM, to acknowledge the importance of _prescriptive_ approaches

I concur.

Thanks for your carefully considered posting Kevin.  Hope this response is 
satisfying.

gem

company www.cigital.com
podcast www.cigital.com/silverbullet
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