Dustin Decker

The Birthday Paradox

The Birthday Problem/Paradox

If you group 23 people born in the United States together, there is a 50% probability that two of them will have the same birth date (month and day).

If you increase the group to 47 people it becomes a virtual certainty that two of them will share a birth date.

There is a great deal of math that goes into this theory (also called the Birthday Paradox). Beyond the math, however, is the simple fact that the most common birthdays in the United States are in late September. (September 16 to October 1 are especially common.) It just so happens that these dates are 9 months after the holidays, Christmas in particular.

The point is that there are certain days on the calendar that are more likely to occur as birth dates than others. There are also certain forms of “randomness” created by computers that are far less random than you might expect – and their predictability makes cracking passwords easier as a result.

Dustin Decker

Hello World! My name is Dustin Decker, and I am a full-time security researcher and student with over twenty years of experience as an information systems engineer. I am currently beginning my senior year pursuing my second bachelor’s degree in applied Cybersecurity (BACS) with the SANS Technology Institute. I anticipate graduating in May of 2024. I am a skilled Information Security Analyst with expertise in risk management framework (RMF), systems development life cycle (SDLC), security life cycle, management of a wide range of vulnerabilities and threats, fundamental business analysis, and project management. Skills: Microsoft Azure FedRAMP, Puppet, Artifactory, Django, Riverbed Steelscript, Riverbed SteelCentral NetShark, Vagrant, Chocolatey, MuleSoft, PostgreSQL, JavaScript, BASH Scripting, PowerShell, RHEL, DevOps, Docker, Visual Studio, BeEf, Bucket Finder, TLS-Scan, CeWL, JQ, Masscan, Metasploit/Meterpreter, Zenmap, Nmap, Mimikatz, SpiderFoot, Unshadow + John, Volatility, and personal new favorite: SRUM-Dump. I specialize in providing IT security expertise and guidance in support of security assessments and continuous monitoring for government (FISMA & NIST) and commercial clients. I am comfortable in heterogenous environments with tens of thousands of hosts.

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