Once upon a time, Cryptography was more or less like a gimmick. Nowadays, nobody will doubt the seriousness of Cryptography as the cornerstone of digital security. This evolution was a long way, not only about the long history but also about the paradigm shift.

Cryptography's biggest change from gimmick to cornerstone is the formalizing of methodologies. In the early days of Cryptography, way back to Caesar's time, it was about bright ideas. There were many bright ideas of transforming text into some obscure forms, and they looked secure. At that time, people just tended to believe that such ideas were secure, because the transformed text appeared impossible to be understood.

While with the extensive use of Cryptography, especially since WWII, "believe to be secure" was no longer acceptable. In order to make sure that the critical information was safely transmitted, scientists started using Maths as the tools to design and analyze Cryptography. Since then Cryptography was not gimmick any more, it became a Science.

But the story is not over. For quite some years, although Cryptography itself was formalized, the methods of using Encryption were like gimmicks. People created so many "creative" ways to use Cryptography, most of the time despite some scientific natures of Cryptography. As a consequence, many of such systems failed.

In order to prevent our digital security from failure, people started applying Formal Methods, which were maturely used in Software Engineering, to the design of Cryptography system. Althought it's an ongoing effort, at least we can see the light of a promising future of security system as a whole.

While look at the physical security industry, the good old industry I am familiar with, although there are blooming of new technologies, it seems some of them are still in Caesar's time.