How to Choose a Password

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- - Why strong passwords are important - -

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- When choosing a password, it’s important to make sure that no one can - guess it — that’s the whole point, right? -

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- If we want to make sure no one can guess our passwords, we need to - think about what adversaries might be trying to guess - them and how they might do it. This is part of a process called - threat modeling. Some adversaries we can think about - are: -

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- People who know us. Our friends know a lot about us, - like our birthday, our pets’ names, our favorite songs, and other - personal information. Even if we’re not worried about friends - guessing our passwords, an adversary might easily find these details - on the Internet, so we shouldn’t use any of these things in our - passwords. -
- People who know a password we’ve used in the past. - Unfortunately, it’s not unusual for passwords to be discovered by - adversaries. This might happen if a website or app we use is - compromised, or if a computer we type our password on has been - infected with malware. This means it’s a bad idea to create a new - password by making a variation of another one. -
- People who know a lot of common passwords. Some - adversaries have compiled “password dictionaries” containing - thousands of commonly used passwords. Even if an adversary is not - specifically trying to find our password, they might use - lists like this to discover our password if it is one of the common - ones. -

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- - The way to make sure that no one can guess our passwords is to make - them completely random. - - When our passwords are randomly generated, they don’t have any - information related to us that friends might be able to guess. If an - adversary learns one of our passwords, they will be no closer to - guessing any of our other passwords. And of course, randomly generated - passwords are very unlikely to be listed in password dictionaries. -

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- - How to generate a random password - -

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- Being truly random is something that people are very bad at. Even when - we think we are being random, there are often patterns - associated with the “random” things we come up with. -

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- When we want to create good, random passwords, one thing we can use is - software (such as our password manager, more on this below) to help us. -

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- Another method is to use a word list and dice to create a random - passphrase. The - Electronic Frontier Foundation, - a digital privacy advocacy group, has created - - a wordlist you can download - - for this purpose. To use this method, you’ll need five dice (or you can - roll a single die five times). Here’s how: -

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- Roll five dice (or one die five times) and read the number from each - so that you have five digits, for example: 1, 6, 3, 5, 2. -
- Look at - - the wordlist - - to find the word next to the number you rolled. - In this case, we find the line 16352 comfort, so our - word word is comfort. -
- Repeat the first two steps until you have at least six words. You - will end up with a random phrase like - comfort tableful booth tulip dandelion stable - which is your new random passphrase. -
- Make up a little story to help remember the passphrase. For example: - “The diner had a comfortable - tableful in the booth with - tulips and dandelions in a - stable vase.” -

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- If an adversary wanted to guess our passphrase, even if they had our - wordlist and knew exactly how we created it, they would need to - correctly guess 30 random die rolls in the right order. The probability - of this is 1 in 221,073,919,720,733,357,899,776. It is - extremely unlikely they would be successful, as it would take - three billion years of making a million guesses every second before - they would be likely to succeed. -

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- - How to remember your passwords - -

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- It’s also important not to use the same password twice. Imagine if we - generate a completely random password and use it for our email account, - and we also use it for a social media site. If an adversary learns our - email address and password for the social media site, they could easily - try that same password on our email account, and since we used the same - random password, they would succeed easily. This is why you should only - use each password for a single site. -

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- When there are a lot of different things we need passwords for, it - quickly becomes hard to remember all of them. Luckily, we can use a - password manager to help us out. Password managers are - software programs that help us securely store our passwords. -

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- Imagine writing down all of our passwords on a sheet of paper, and then - scrambling them all up according to a secret pattern. Even though - someone might look at the paper, they won’t be able to figure out any - of our passwords without knowing the secret pattern we used to scramble - them. Password managers use a similar idea; they use a - master passphrase to encrypt the list of all of our - passwords. The master passphrase is like the scrambling pattern: an - adversary can access the list of all our passwords if and only if they - discover the master passphrase. -

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- It’s very important to use a long, randomly generated master passphrase - because all of our passwords are only as good as our master passphrase. - When we use a password manager, we only need to remember our passphrase - to unlock our list of passwords. The password manager stores all of our - other passwords for us. -

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- Another benefit to using a password manager is that they help us - generate new passwords when we need them. Rather than rolling dice - every time we sign up for a new account, we can let your password - manager come up with completely random password for us. Since our - password manager also stores the new password for us, we never even - need to know what it is! We can just copy and paste it when we need to - log in. -

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- There are several password managers available. You should do some - research to find one that will work for you. Here are a few suggestions - to start with: -

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