CORDIC stands for COordinate Rotation DIgital Computer. It is an iterative method for calculating trigonometric and related functions using only shifts, adds, and table lookups instead of expensive multiplications or division. That made it attractive in older processors, small embedded devices, and hardware blocks where silicon area, power, and speed were tightly constrained.
In cyber security, CORDIC matters because hidden math routines can be part of trusted computing paths: firmware, floating-point units, signal-processing chips, and crypto-adjacent accelerators may all rely on them. Security reviewers care about CORDIC implementations because approximation errors, edge cases, and undocumented behavior can affect correctness and reproducibility. Attackers may try to exploit such weaknesses through crafted inputs, while defenders use reverse engineering and testing to verify that the implementation matches its specification. The 8087 FPTAN path is a good example of how a compact algorithm can sit beneath an interface that users assume is simple.