Peter Luhn came up with the idea of using math to verify and store information, Birthday problem explains the collisions in Hash tables, Rabin-Karp algorithm uses rolling hash to search strings. We’ve talked so much about hash, yet not a single time was the definition of the hash function itself provided. When did hashing first appear? In 1956 the idea of hashing was for the first time defined by Arnold Dumey. His passion for cryptography since 14 and mathematics degree from Columbia University.