The RSA patent, 4,405,829, was pretty innovative and also quite useful, although even it had been invented in secret a year earlier by the British. That said,

The RSA patent, 4,405,829, was pretty innovative and also quite useful, although even it had been invented in secret a year earlier by the British. That said, I don't think there's any evidence that the existence of the patent system prompted its invention, and so I wouldn't call this an argument in favor of patents.