(Happy Together) ((LINK)) Full Crack [Password]
Netflix is testing a way to crack down on password sharing. The streaming service has been asking some users of the popular streaming site to verify that they live with the holder of the account. Jenny Kane/AP hide caption
(Happy together) full crack [Password]
Since very few systems have support for one-time tokens (dynamic passwords which are only used once), everyone should be aware of how to select strong passwords. If a malicious user can get hold of or 'crack' your password they can access the system with your identity and with your access rights.
An alphanumeric password contains numbers, letters, and special characters (like an ampersand or hashtag). In theory, alphanumeric passwords are harder to crack than those containing just letters. But they can also be harder to both create and remember.
And remember that hackers can crack even the strongest password. The best way to strengthen your password is to add in another factor, such as something you have in your possession. So-called "two-factor authentication" is much harder for a hacker to manipulate and crack. We've written up a white paper about this practice, and we encourage you to check it out.
A brief note - this article is about the theory of how to crack hashed passwords. Understanding how cybercriminals execute attacks is extremely important for understanding how to secure systems against those types of attacks.
Unfortunately, the hashing functions which are used for hashing passwords aren't always as secure as generally approved hash functions. For example, the hashing function used for old Windows devices is known as LM Hash, which is so weak that it can be cracked in a few seconds.
If a password is insecure (let's say someone uses a password 5 characters long), it can be relatively easily cracked. For example, a password of 5 lowercase characters can only be used to create 11,881,376 different passwords (26^5).
For example if the password you're trying to crack is 8 characters long but uses numbers (10 digits), lowercase letters (26), uppercase letters (26), and some special characters (10), the number of possible passwords jumps to 722,204,136,308,736 - which is A LOT of storage space, when you realize each is hashed with a hashing function like SHA-256.
Rainbow tables address this issue by offering reduced storage needs, but they take more time to compute the potential passwords. At the most basic level, these are essentially pre-computed lookup tables which enable you to quickly find the plaintext which matches the hash you have. If the hash and plaintext are contained in the table you have - similar to dictionary attacks - you're only looking to see if the password is contained in the table you have. If it isn't, you won't be able to crack the password. You can find these online for free or for purchase.
First, a layered defense of all systems. If you can prevent compromise of your systems via other methods (so the attacker can't get a copy of your hashed passwords), the attacker won't be able to crack them.
You can also use salting, which adds a random value to the password before encrypting it. That means that the precomputed value you've found (which matches the hash) won't work. The encrypted text is not based solely on the unencrypted text. Because the salt is different for each password, each needs to be cracked individually.
One other method designed to increase the difficulty of cracking the password is to use a pepper. Pepper is similar to salt, but while a salt is not secret (it's stored with the hashed password), pepper is stored separately (for example, in a configuration file) in order to prevent a hacker from accessing it. This means the pepper is secret, and its effectiveness depends on this.
Use a password manager. These free tools encrypt and store all of your passwords. Then they automatically insert your password when you log in to an account. Some managers even include a random password generator that creates hard-to-crack passwords with the click of a mouse. Popular password managers include LastPass, 1Password, and Dashlane.
A salt SHOULD be used however. Password cracking is all about time/effort. No password/hash is invincible. It is all about forcing the attacker to spend more time than he is willing to spend on your password tables.
Space-wise parallelism is when the attacker has several hashes to crack (that's the LinkedIn situation). With unsalted hashes, the attacker can hash one potential password and look the result up in the whole list of hashes he wants to crack.
Ptacek doesn't actually say that a salt would not have prevented LinkedIn passwords from being cracked. I would have to argue that depending on the size of the salt it would have even protected the worst of the passwords.
where you can see at a glance that SHA('password')=5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8, looking up the original password from the hash is all too simple. We want the cracker to have to do some work for it.
So salting makes it so each hash has to be cracked individually, because to do it, if the cracker has the salts, the cracker has to append/prepend the salt to each common password he tries. 2 different users could use the simple password password, but cracking that will be 2 entirely separate jobs for the cracker, because of the salt. So cracking all the passwords will take longer.
Stop requiring passwords altogether, and let people log in with Google, Facebook, Twitter, Yahoo, or any other valid form of Internet driver's license that you're comfortable supporting. The best password is one you don't have to store.
If you're really unlucky, the developers behind that app, service, or website stored the password in plain text. This thankfully doesn't happen too often any more, thanks to education efforts. Progress! But even if the developers did properly store a hash of your password instead of the actual password, you better pray they used a really slow, complex, memory hungry hash algorithm, like bcrypt. And that they selected a high number of iterations. Oops, sorry, that was written in the dark ages of 2010 and is now out of date. I meant to say scrypt. Yeah, scrypt, that's the ticket.
It's unlikely that massive cracking scenarios will get any slower. While there is definitely a password length where all cracking attempts fall off an exponential cliff that is effectively unsurmountable, these numbers will only get worse over time, not better.
Pick your new password hash algorithms carefully, and move all your old password hashing systems to much harder to calculate hashes. You need hashes that are specifically designed to be hard to calculate on GPUs, like scrypt.
Like the password, the passphrase is a credential for accessing secure information, applications and networks. The passphrase, however, is a series of words and characters strung together to form a lengthy phrase that is more likely to be unique to you. Because of its length and added complexity, the passphrase is a harder nut for the hacker to crack. And, because the passphrase could be made up of an infinite number and order of words, numerals and symbols, the concept in itself promises to be a more effective long-term solution. 350c69d7ab