Is the password FFFFFggggg&&&&&22222 safe from being guessed? [closed]

Question

It is 20 characters long, mixes alphanumeric and special symbols. It is one among ** 20.

Answer 1

Well I guess now that you stuck it on here, someone will probably add it to a dictionary list, so that specific one probably isn't anymore.

Answer 2

The problem with this password is that it is based on a pattern. As long as your pattern remains a secret, then it has some value. But, as soon as your pattern becomes known, then it is only as good as a 4 character password.

The best case is to have a password that is still strong, even if the world knows how you generated it.

Answer 3

There are lots of hackers out there trying to crack passwords. At least one of them is bound to have rules for Repeated Characters high up in their guessing order.

Answer 4

The security of a password depends roughly on its entropy, which itself is a metric of how much information it contains. The password "AAAAA" has terrible entropy, since it's the same character repeated five times. On the other hand, "e^#Yc" is, whilst still way too short, much better. It can't be described as easily.

Relying entirely on repeated characters is bad because there just aren't that many ways to do so. You only have four unique characters in the password. If I tried every way to combine four alphanumeric/symbol characters, I'd get 72^4=26873856 combinations. If I were to use up to five copies of each symbol, then there would be 72^4 * 5^4 combinations (since I can use 1, 2, 3, 4, or 5 of each character, which is only 5 choices). This gives 16796160000 combinations. Whilst better, it's still not that good. Using ten random alphanumeric/symbol characters would give 3743906242624487424 combinations, for example.

I think your problem is a misunderstanding of password strength. Mixing letters and symbols, using capital letters, and so forth are ways to increase the search space of a password. The larger the search space, the harder it is to break a password, since the number of possible passwords is (search space)^(length).

However, if your password is either very short or effectively very short (repeated characters are an example of this), then it's still weak!

Answer 5

It would depend on how the hypothetical attacker approaches guessing the password.

Against a simple brute-force attack (i.e. trying every possible combination in the available key space) this password would most likely hold up very well indeed, because it's very long. Unfortunately, most attackers won't be using pure brute-force attacks.

It could also be expected to do well against a pure dictionary attack, for obvious reasons.

However, a clever attacker might be reasonably expected to account for patterns like repeated or sequential characters in their attack. Since this password's structure is very regular (5 repetitions each of just 4 characters) it would fall much more quickly to an attack that's looking for patterns.

Suppose an attacker were to gain access to a password database containing a hashed version of this password (as happens all the time.) Let's say the attacker has already exhausted their dictionary attacks and is turning to pattern-based attacks. Such an attack could be expected to take into account logical sequences (e.g. 12345,) spatial sequences (e.g qwertyuiop,) repetitions, etc. and various combinations of them. I don't know if I could reliably estimate the size of such a key space, but it would certainly be significantly smaller than if the key were truly random. This question has some discussion about the principles behind pattern-based password cracking.

Answer 6

Try this service: https://howsecureismypassword.net/

According to this service, cracking your password would take 43 quintillion years with a regular computer.