What is the easiest way to encrypt a password when I save it to the registry?

Question

Currently I\'m writing it in clear text oops!, it\'s an in house program so it\'s not that bad but I\'d like to do it right. How should I go about encrypting this w

Answer 1

Tom Scott got it right in his coverage of how (not) to store passwords, on Computerphile.

https://www.youtube.com/watch?v=8ZtInClXe1Q

1. If you can at all avoid it, do not try to store passwords yourself. Use a separate, pre-established, trustworthy user authentication platform (e.g.: OAuth providers, you company's Active Directory domain, etc.) instead.

2. If you must store passwords, don't follow any of the guidance here. At least, not without also consulting more recent and reputable publications applicable to your language of choice.

There's certainly a lot of smart people here, and probably even some good guidance given. But the odds are strong that, by the time you read this, all of the answers here (including this one) will already be outdated.

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The right way to store passwords changes over time.

Probably more frequently than some people change their underwear.

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All that said, here's some general guidance that will hopefully remain useful for awhile.

1. Don't encrypt passwords. Any storage method that allows recovery of the stored data is inherently insecure for the purpose of holding passwords - all forms of encryption included.

2. Process the passwords exactly as entered by the user during the creation process. Anything you do to the password before sending it to the cryptography module will probably just weaken it. Doing any of the following also just adds complexity to the password storage & verification process, which could cause other problems (perhaps even introduce vulnerabilities) down the road.

   • Don't convert to all-uppercase/all-lowercase.
   • Don't remove whitespace.
   • Don't strip unacceptable characters or strings.
   • Don't change the text encoding.
   • Don't do any character or string substitutions.
   • Don't truncate passwords of any length.

3. Reject creation of any passwords that can't be stored without modification. Reinforcing the above. If there's some reason your password storage mechanism can't appropriately handle certain characters, whitespaces, strings, or password lengths, then return an error and let the user know about the system's limitations so they can retry with a password that fits within them. For a better user experience, make a list of those limitations accessible to the user up-front. Don't even worry about, let alone bother, hiding the list from attackers - they'll figure it out easily enough on their own anyway.

4. Use a long, random, and unique salt for each account. No two accounts' passwords should ever look the same in storage, even if the passwords are actually identical.
5. Use slow and cryptographically strong hashing algorithms that are designed for use with passwords. MD5 is certainly out. SHA-1/SHA-2 are no-go. But I'm not going to tell you what you should use here either. (See the first #2 bullet in this post.)
6. Iterate as much as you can tolerate. While your system might have better things to do with its processor cycles than hash passwords all day, the people who will be cracking your passwords have systems that don't. Make it as hard on them as you can, without quite making it "too hard" on you.

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Most importantly...

Don't just listen to anyone here.

Go look up a reputable and very recent publication on the proper methods of password storage for your language of choice. Actually, you should find multiple recent publications from multiple separate sources that are in agreement before you settle on one method.

It's extremely possible that everything that everyone here (myself included) has said has already been superseded by better technologies or rendered insecure by newly developed attack methods. Go find something that's more probably not.