Operational security (OPSEC) is a crucial concept that is highlighted in both of the provided podcast episodes.

In the History Daily episode on D-Day deception, the Allies used various OPSEC measures such as staged events, leaked misinformation, and the use of double agents to mislead the Germans about the true location of the D-Day invasion. These intricate OPSEC tactics were essential for maintaining the credibility of the deception plan and diverting German forces away from Normandy.

Similarly, in the Darknet Diaries episode featuring Sam the Vendor, the focus is on the detailed OPSEC measures employed by the dark web drug dealer to maintain anonymity and avoid detection by law enforcement. Sam's story demonstrates the importance of OPSEC in the context of cybercrime and illicit online activities.

Both episodes illustrate how OPSEC principles, from information control to the use of deception and anonymity techniques, can be applied in different domains to protect critical assets and information.