#Cisco ios upgrade password

Secondly, the smaller the hash, the more likely that two different inputs could result in the same output which means that even if the attacker didn't get the right password, they could still get into the system. Also, if the output of a hash is relatively short, it's easier to keep a file with all of the possible passwords.

#Cisco ios upgrade password

This is because a hashing algorithm that is very efficient to run means that an attacker can brute force every password combination very quickly. The last hurdle to overcome with hashing is that the algorithm should be 'expensive' or time consuming to run. This prevents the hash from two users from matching. Then, when the system wanted to check whether a userвЂ™s password input matched the stored value, the system would tack on the salt and run it through the algorithm. Every password would include a unique salt and that salt would be stored alongside the resulting hash. Basically, a salt is a string that gets added onto the password and then ran through the hashing algorithm to create a unique hash. To combat this, password storage can include a 'salt'. Secondly, if two users used the same password (say 'password123'), we would know that because their hashes match each other that they have the same password which would save the attacker some time. So, for example, our file for the MD5 algorithm could look like this:ДЄnd now it's really easy to figure out the input if we know the hash.

If we went ahead and precomputed all of hashes for a large number of inputs and stored them in a file, every time we came across a hash and wanted to know it's original value we could just look up that hash in the file and we would know the input. Every time you put the same input into the hashing algorithm you will always get the same output. However, hashing has a different problem that we have to cope with. To be clear, for things like passwords, we want them to be stored as a hash not encrypted because if the key is compromised, so is your password.

Output from an encryption algorithm can be fed back into the algorithm with the key to get the original input. An encryption algorithm is two way and requires a key. Output from a hashing algorithm cannot be put back into the algorithm to get the original input. Hashing and encryption are different from one another. Let's go over password basics and explain some things. Using the secret keyword forces the system to use MD5 hashing but this still isn't the best we could use. We have to turn on password encryption on the system but even this is a pretty weak encryption algorithm. Most people going through CCNA training will know that by default, Cisco IOS and IOS-XE devices do not hash passwords in the configuration.