I know restricting access of a file, is a important measure of security.
If we read the Payment Card Industry's Data Security Standard (aka PCI-DSS), we can see a requirement where control access must be applied to mitigate any risk of a sensitive encrypted data be leaked from the system.
Other important requirement define minimum data to be kept encrypted, again mitigating possible leak.
I would like to understand how safe my system is without those mitigations actions. What are the risk on trusting only on Encryption Algorithm.
I would like to know precisely if is considered safe keeping a file encrypted by asymmetric encryption algorithm inside a public & not trusted environment.
How a malicious agent can break file encryption? By brute-force? What are the exactly risks by leaving a encrypted file in a public environment where anyone can read it?
Consider a situation where entropy used to generate the keypair is perfect.