Public key cryptography is a good example, which solved the seemingly impossible to solve key-distribution problem: https://www.coursera.org/learn/cryptography

Public key cryptography is a good example, which solved the seemingly impossible to solve key-distribution problem: https://www.coursera.org/learn/cryptography/lecture/be3ae/the-public-key-revolution https://www.coursera.org/learn/cryptography/lecture/be3ae/th...