My bank limits my password to 14 characters and I suspect they're encrypting with MD5 or an SHA hash, unsalted.
Are there rainbow tables that contain every possible hash up to 14 characters?
it depends on the character ranges used, but 10 characters seems to be the limit in the the downloads here (lower for full character ranges).
Related
I am working on a Desktop Application using VB.net with an existing database. Including the user's username and password, I want to do the login window using the existing password but it was hashed password. May I know what hash algorithm use in this data X8NUoMVWb/w6D4QdmumxoQ==?
You can make an educated guess simply by looking at the length of the hash, as generally there's only a handful of popular hashing algorithms used for passwords, all with their own distinct output lengths:
Hash
Output length (bytes)
Output length (bits)
MD5
16
128
SHA-1
24
160
SHA-2 (SHA256)
32
256
SHA-2 (SHA512)
64
512
You can never know for sure because while different hashing algorithms have different output sizes, the output can always be truncated (or padded with random bytes).
That said, X8NUoMVWb/w6D4QdmumxoQ== is a Base64-encoded binary value which decodes to a 16-byte value. 16 bytes is 128 bits - it's very likely this is an MD5 hash value.
The 16 bytes convert to Base 16 (hexadecimal) are 5FC354A0C5566FFC3A0F841D9AE9B1A1.
This MD5 hash doesn't appear in any freely available leaked password databases or hash-reverse services I tried.
Note that systems like bcrypt generate an output string which is not just a hash-value, but actually a data structure containing the hash and other data. In bcrypt's case the string always starts with $2 which will never appear in a Base16 or Base64-encoded string.
How can I check whether an input string is in the form of a Md5 hash or not in Rails3.0?
Consider all 32-digit long hexadecimal numbers (ie. consisting solely of letters a-f and digits 0-9) to be md5 hashes.
I don't know if md5's codomain is the whole space of 32-digit long hexadecimals, but a hash should ideally satisfy the condition so you may just assume it is.
Well met!
I'm unfortunately not a programmer, but I need some help in order to solve a great mystery of mine. I want to generate all combinations of an 8 character long string with regards to the alphabet, numbers 0-9 and the size of all the letters. The plain truth is that I want to access an old encrypted volume for which I've forgotten my password. However, I know it's 8 characters long (yeah, unsecure), and I know that I used a combinations of numbers and letters of all sizes.
Any pointers in the right direction would be extremely helpful!
If your password is 8 characters long, and can contain 26 all lower case or all upper case letters plus 10 digits, then you would be looking at (26 + 10) ^ 8 = 2,821,109,907,456 combinations. You might be able to crack it provided you can programatically acess it at something like 500 million tries per second. That would not take more than 2,821,109,907,456 / 500,000,000 = 5,643 seconds - which is a little less than an hour and a half. If however you mean both upper case and lower case letters, then the number of combinations escalates to (26 + 26 + 10) ^ 8 = 360,040,606,269,696 combinations and would take roughly 128 times longer or 5,643 * 128 = 722,304 seconds. Since there are 86,400 seconds in a a day, dividing 722,304 by 86,400 yields 8.36 days. That is assuming you can feed it strings containing the password that fast.
Anything you can do to try and remember a portion of the password would be helpful. If you must enter the password manually, then it is not solvable. If you have an old computer or old hard drive, then try looking around on it for the password or perhaps a hint for the password that would allow you to reconstruct it. Did you ever send the password in an email or email attachment to someone? If so, you might be able to retrive it that way. Could you possibly have written it down somewhere? Where would that be if you had? Does the password you selected have a special meaning such that if you remember one or two digits, you can figure out the rest of the password from that?
Hello I was trying to find a good way to hash a set of numerical numbers which its output would be under 20 characters that are positive and unique. Any one have any suggestions?
For hashing in general, I'd use the HASHBYTES function. You can then convert the binary data to a string and just pick the first 20 characters, that should still be unique enough.
To get around HASHBYTES limitations (8000 bytes for instance), you can incrementally hash, e.g. for each value concat the previous hash with the value to be added and hash that again. This will make it unique with order etc. and unless you append close to 8000 bytes in one value it will not cause data truncation for the hashing.
I would like to create unique string columns (32 characters in length) from combination of columns with different data types in SQL Server 2005.
I have found out the solution elsewhere in StackOverflow
SELECT SUBSTRING(master.dbo.fn_varbintohexstr(HashBytes('MD5', 'HelloWorld')), 3, 32)
The answer thread is here
With HASBYTES you can create SHA1 hashes, that have 20 bytes, and you can create MD5 hashes, 16 bytes. There are various combination algorithms that can produce arbitrary length material by repeated hash operations, like the PRF of TLS (see RFC 2246).
This should be enough to get you started. You need to define what '32 characters' mean, since hash functions produce bytes not characters. Also, you need to internalize that no algorithm can possibly produce hashes of fixed length w/o collisions (guaranteed 'unique'). Although at 32 bytes length (assuming that by 'characters' you mean bytes) the theoretical collision probability of 50% is at 4x1038 hashed elements (see birthday problem), that assumes a perfect distribution for your 32 bytes output hash function, which you're not going to achieve.