Sr. Pen testers make $300-$400K&#x2F;year.  The companies they work for charge a 50% markup.  For short projects on a tight timeline, the costs are even higher.<p>I don&#x27;t know of any other profession that <i>does</i> do code review with explicit tasks of finding vulnerabilities in the code.<p>And pen testers love to critique the many, many, many ways in which CSPRNG can fail - even when appropriate algorithms are chosen, <i>and correctly implemented</i> - there are still ways in which compiler options can expose you to side-channel attacks.  The Juniper Dual-EC vulnerability would have been identified in the first 5 minutes (Dual_EC_DRBG - WTF?!) someone skilled in that arena was looking at that section of code.<p>A hundred people gives you enough breadth to find people who are not only familiar with the higher level security concepts (IPSec, Firewalling, packet filtering, SSL, SSH, etc, etc...) in the ScreenOs code, but also people who can evaluate tool chains, compiler output, etc.. And get the job done in a reasonable period of time (90 days).<p>There is absolutely no way you could scrub your own code with your own developers in a short period of time - not only do they have endless internal responsibilities, they aren&#x27;t experts in vulnerability assessment (typically) -, there just aren&#x27;t enough of them to do this in a reasonable period of time.  I can&#x27;t believe that Juniper has large numbers of $400k&#x2F;year pen testers just sitting on staff.  Companies usually only hire a few of those people for several weeks a year - relying on code review the rest of the year.<p>Also - remember, it&#x27;s unclear whether someone internal in Juniper installed this code in the first place - you <i>want</i> a third party to check everything over.  Leadership has to do something very meaningful here, beyond just, &quot;we had our engineers review the code&quot; - bringing in a massive third-party high-level audit is the sort of thing that will demonstrate transparency.