re: How to Securely Store a Password in Java VIEW POST


A couple comments:

  1. Aside from making sure you're not retaining references to it forever, worrying about trying to overwrite the the String containing the user's password is basically futile. There are likely lots of copies made of that string along the way. If someone has access to your program's memory, it's not protected anyway.

  2. At this point in time, please use argon2 or scrypt as your password hashing algorithm. They force much larger use of memory which makes brute force attack schemes less feasible on GPUs and more expensive on ASICs and FPGUs.

  3. Using a more expensive password hashing scheme should never be a vector for a DoS attack. The correct solution is to implement exponential backoff on repeated failed login attempts: the first failure lets you try again in 100ms, the second failure in 200ms, the third in 400ms, etc. The exception is in environments that specify otherwise, such as health care in the USA, where HIPAA specifies three tries then lockout.


Fair points. Thanks for taking the time to read and comment. These are definitely things I'll have to change if I implement this commercially. (This example was for a term project for a class I took.)

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