Death Note: L, Anonymity & Eluding Entropy
Applied Computer Science: On Murder Considered As STEM Field—using information theory to quantify the magnitude of Light Yagami’s mistakes in Death Note and considering fixes
In the manga Death Note, the protagonist Light Yagami is given the supernatural weapon “Death Note” which can kill anyone on demand, and begins using it to reshape the world. The genius detective L attempts to track him down with analysis and trickery, and ultimately succeeds. Death Note is almost a thought-experiment-given the perfect murder weapon, how can you screw up anyway? I consider the various steps of L’s process from the perspective of computer security, cryptography, and information theory, to quantify Light’s initial anonymity and how L gradually de-anonymizes him, and consider which mistake was the largest as follows:
Killing through heart attacks does not just make him visible early on, but the deaths reveals that his assassination method is impossibly precise and something profoundly anomalous is going on. L has been tipped off that Kira exists. Whatever the bogus justification may be, this is a major victory for his opponents. (To deter criminals and villains, it is not necessary for there to be a globally-known single anomalous or supernatural killer, when it would be equally effective to arrange for all the killings to be done naturalistically by ordinary mechanisms such as third parties/police/judiciary or used indirectly as parallel construction to crack cases.)
