What I found most interesting about the "Vox Ex Machina" podcast was Homer Dudley’s choice to use a pair of vinyl phonograph records as the key both the encryption and decryption process. Prior to listening to this podcast, I had not considered noise could be used as an encryption method. What surprised me even more was the security of Dudley’s encryption method.The single use keys were extremely secure because the enemy cannot replicate a record with the same random noises. Furthermore, even if the enemy was able to lay their hands on the keys, it would be useless without the SIGSALY machine and without knowledge of the agreed time to conference. To add an additional layer of security, the SIGSALY could only function in a narrow temperature range so it needed to be maintained specifically by an entire division of engineers. Enemies who got their hands on the machines might lack the knowledge about how to maintain and use the machine, thus rendering it unusable.

The podcast producer added audio tracks to the podcast which helped to better tell the story. For example, in the beginning of the podcast, the narrator is talking about the debut of the Voder at the New York World’s Fair, so he plays a recording of the Voder in action. A second example of this is when the narrator explains that as the SIGSALY machine processes voices, the voices are slightly mutated but the message is still intelligible. He then inserts a recording of what a SIGSALY communication might sound like to illustrate his statement. The variation in sounds also keeps the listener interested because he or she is not listening to the same voice speak for 20 minutes.

The narrator states an entire division of engineers was necessary to maintain the machine because it was so technically demanding. To make the technical aspects of the material accessible, the producer omits the technical details of the machine’s processes that were nonessential to the listener’s understanding of the SIGSALY. This way the foundational ideas are not lost but the processes that might confuse the general audience are not included.

This podcast inspired me to consider researching some non-conventional applications cryptography for my podcast. I will also aim to include different voices or sounds as this podcast has done to keep my audience captivated.