what do you call a cryptographic method or product considered bogus or fraudulent?

A cryptographic method or product considered bogus or fraudulent is commonly called "snake oil." This term is borrowed from the historical concept of snake oil as a type of fraudulent medicinal product, implying that such cryptographic products make misleading claims about their security but lack robust technical foundations or effectiveness. Snake oil cryptography often includes secret algorithms, unrealistic claims of unbreakability, technobabble, or ad hoc modifications of standard cryptographic methods that weaken security.