Linked by Howard Fosdick on Sat 10th Nov 2012 07:28 UTC
Bugs & Viruses If you want to ensure you have adequate passwords but don't have the time or interest to study the topic, there's a useful basic article on how to devise strong passwords over at the NY Times. It summarizes key points in 9 simple rules of thumb. Also see the follow-up article for useful reader feedback. Stay safe!
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RE[13]: make 'm long
by Laurence on Mon 12th Nov 2012 13:48 UTC in reply to "RE[12]: make 'm long"
Laurence
Member since:
2007-03-26


Why can't you target hash generators? After all, to generate your hash, you're basically using a passphrase and the website for the salt.

I'd already answered that.

The method used to create the hash is irrelevant in this specific context. Whether you used a hash generator or randomly mashed the keys on the keyboard - the password is still a random character string and it's that password that you need to crack. Knowing the method used to create the password would, at most, only tell you which characters to include in your brute force attack (eg base64 encoded sha512 hashes will have 0-9. a-z, A-Z + and /. Where as another random character string could include different characters.

What you're thinking about is the storage of passwords in hashes - which is completely different.

If you store a password in a hash then you can use a hash table to match hash strings and effectively reverse engineer the originating password. But the password itself wouldn't be a hash. That password could be a passphrase or any other password that the user chose.

So using a hash as a password itself doesn't leave itself vulnerable to detection based on the hash generator used. Using such a generator is just an arbitrary method to produce an arbitrary random string.


If passphrase cracking is as easy as you say it is, then it's just as easy for a cracker to figure out the passphrase you use to generate the hash.

No, you're getting yourself completely muddled there.
The only possible way you could find out the passphrase for the hash used in my method would be if you found out the output password; and if they know that then they already have your password so there's no bloody point trying to find the passphrase used to generate that password as they already have your login details lol.

My method is little different to randomly mashing a keyboard in terms of the password generated. Except I provide a way to exactly repeat the random mashing in a secure way. However the attack would only ever have exposure to the end result so could not and would not care about the method used to create the password (ie whether it was random keyboard mashing, password generator or a hash generator).

Reply Parent Score: 2

RE[14]: make 'm long
by kwan_e on Mon 12th Nov 2012 14:02 in reply to "RE[13]: make 'm long"
kwan_e Member since:
2007-02-18

The only possible way you could find out the passphrase for the hash used in my method would be if you found out the output password; and if they know that then they already have your password so there's no bloody point trying to find the passphrase used to generate that password as they already have your login details lol.


They don't need to know your password. They just need to know if the hash they generated managed to authenticate themselves to a site as you. ie:

1) Estimate your passphrase
2) Generate the hash
3) Use the hash to try and authenticate

Sure, it's a few extra steps than

1) Estimate your passphrase
2) Use the passphrase to try and authenticate

It's one more level of indirection, but it still begins with a passphrase.

Reply Parent Score: 2

RE[15]: make 'm long
by Laurence on Mon 12th Nov 2012 14:28 in reply to "RE[14]: make 'm long"
Laurence Member since:
2007-03-26


They don't need to know your password. They just need to know if the hash they generated managed to authenticate themselves to a site as you. ie:

1) Estimate your passphrase
2) Generate the hash
3) Use the hash to try and authenticate

Sure, it's a few extra steps than

1) Estimate your passphrase
2) Use the passphrase to try and authenticate

It's one more level of indirection, but it still begins with a passphrase.

lol it's not nearly as simple as that.

Even just one character different will generate a completely different string of characters. So they have to know all of the following precisely:

* how you decide your salt (ie is it the full website address inc protocol handler, the URI or just the website name?

* the passphrase (obviously)

* how the salt is encoded into the passphrase (eg is the salt and passphrase concatenated, and if so in which order? or is the passphrase hashed then the hash salted? etc)

* exactly which encoding algorithm used (there's multiple different routines for sha alone. So it's not even a simple as predicting everyone would use sha512)

* which output encoding (will the output be a standard ASCII character string? Will it be Base64 encoded? is it unicode?)

* has there been any post processing (eg has the output hash been tampered with?)

Sure you could make a number of assumptions, but the level of complexity involved is massive and the difference between getting one details even 99% right but not completely accurate is the difference between eventually cracking the password and never cracking it ever.

So no, in all practicality you cannot reverse engineer in the method you describe and using "raw" passphrases like you keep advocating is still quite a bit less secure in comparison.


Seriously mate, I urge you to read up on this stuff as there's clearly some large gaps in your understanding here; which would be fine if you were asking questions, but instead you're trying to argue facts based on these gaps of knowledge and -with the greatest of respect- it's getting quite frustrating having to debunk all these misconceptions which you'd easily be able to debunk yourself if bothered to do a little independent research ;)

Reply Parent Score: 2