How Do Cryptographic Failures Contribute to a Broken Access Control?

A lot of applications still have certain ports open where data can be fetched or think of you and I are using some channel of communication which is on HTTP. You would see a lot of places wherein there are certain bank pages. These things become so common. There's nothing that we can do and who to blame for only ourselves. If keys are not being stored properly or if the keys are not managed properly, what will we do?