Robert Carmichael

Robert Carmichael was a mathematician known for his work in number theory and graph theory, particularly for identifying a specific problem called Carmichael numbers—composite numbers that deceptively pass certain primality tests, making them appear prime. These numbers are important in cryptography because they illustrate limitations in some algorithms used to verify whether a number is prime. Carmichael's research helped deepen our understanding of number properties and contributed to improving methods for primality testing, which are essential for secure digital communications and cryptographic systems.