Topic: A public service announcement - page 2. (Read 3813 times)

No. They are designed to quickly compute a mostly unique digest for a preimage.

This is what hashes were designed to do.

Performance test results on my laptop:
Results are here shorten to fit php web notes ...
This was tested with 1024000 bytes (1000 KB) of random data, md4 always gets the first place, and md2 always get the last place

Results: (in microseconds)
   1.  md4                           5307.912
   2.  md5                           6890.058
   3.  crc32b                        7298.946
   4.  crc32                         7561.922
   5.  sha1                          8886.098
   6.  tiger128,3                    11054.992
   7.  haval192,3                    11132.955
   8.  haval224,3                    11160.135
   9.  tiger160,3                    11162.996
  10.  haval160,3                    11242.151
  11.  haval256,3                    11327.981
  12.  tiger192,3                    11630.058
  13.  haval128,3                    11880.874
  14.  tiger192,4                    14776.945
  15.  tiger128,4                    14871.12
  16.  tiger160,4                    14946.937
  17.  haval160,4                    15661.954
  18.  haval192,4                    15717.029
  19.  haval256,4                    15759.944
  20.  adler32                       15796.184
  21.  haval128,4                    15887.022
  22.  haval224,4                    16047.954
  23.  ripemd256                     16245.126
  24.  haval160,5                    17818.927
  25.  haval128,5                    17887.115
  26.  haval224,5                    18085.002
  27.  haval192,5                    18135.07
  28.  haval256,5                    18678.903
  29.  sha256                        19020.08
  30.  ripemd128                     20671.844
  31.  ripemd160                     21853.923
  32.  ripemd320                     22425.889
  33.  sha384                        45102.119
  34.  sha512                        45655.965
  35.  gost                          57237.148
  36.  whirlpool                     64682.96
  37.  snefru                        80352.783
  38.  md2                           705397.844

md2           32
md4           32
md5           32
sha1          40
sha256        64
sha384        96
sha512       128
ripemd128     32
ripemd160     40
ripemd256     64
ripemd320     80
whirlpool    128
tiger128,3    32
tiger160,3    40
tiger192,3    48
tiger128,4    32
tiger160,4    40
tiger192,4    48
snefru        64
gost          64
adler32        8
crc32          8
crc32b         8
haval128,3    32
haval160,3    40
haval192,3    48
haval224,3    56
haval256,3    64
haval128,4    32
haval160,4    40
haval192,4    48
haval224,4    56
haval256,4    64
haval128,5    32
haval160,5    40
haval192,5    48
haval224,5    56
haval256,5    64

If you create a modification for SMF that uses advanced password hashing and gracefully upgrades from old hash types, I will use it.

Bcrypt is probably fine, though I tend to prefer many iterations of traditional hash algorithms. This is what hashes were designed to do. PGP does it, and it's used in many crypto standards.

Description
string crypt ( string $str [, string $salt ] )

crypt() will return a hashed string using the standard Unix DES-based algorithm or alternative algorithms that may be available on the system.

Some operating systems support more than one type of hash. In fact, sometimes the standard DES-based algorithm is replaced by an MD5-based algorithm. The hash type is triggered by the salt argument. Prior to 5.3, PHP would determine the available algorithms at install-time based on the system's crypt(). If no salt is provided, PHP will auto-generate either a standard two character (DES) salt, or a twelve character (MD5), depending on the availability of MD5 crypt(). PHP sets a constant named CRYPT_SALT_LENGTH which indicates the longest valid salt allowed by the available hashes.

The standard DES-based crypt() returns the salt as the first two characters of the output. It also only uses the first eight characters of str, so longer strings that start with the same eight characters will generate the same result (when the same salt is used).

On systems where the crypt() function supports multiple hash types, the following constants are set to 0 or 1 depending on whether the given type is available:

    CRYPT_STD_DES - Standard DES-based hash with a two character salt from the alphabet "./0-9A-Za-z". Using invalid characters in the salt will cause crypt() to fail.
    CRYPT_EXT_DES - Extended DES-based hash. The "salt" is a 9-character string consisting of an underscore followed by 4 bytes of iteration count and 4 bytes of salt. These are encoded as printable characters, 6 bits per character, least significant character first. The values 0 to 63 are encoded as "./0-9A-Za-z". Using invalid characters in the salt will cause crypt() to fail.
    CRYPT_MD5 - MD5 hashing with a twelve character salt starting with $1$
    CRYPT_BLOWFISH - Blowfish hashing with a salt as follows: "$2a$", a two digit cost parameter, "$", and 22 digits from the alphabet "./0-9A-Za-z". Using characters outside of this range in the salt will cause crypt() to return a zero-length string. The two digit cost parameter is the base-2 logarithm of the iteration count for the underlying Blowfish-based hashing algorithmeter and must be in range 04-31, values outside this range will cause crypt() to fail.
    CRYPT_SHA256 - SHA-256 hash with a sixteen character salt prefixed with $5$. If the salt string starts with 'rounds=$', the numeric value of N is used to indicate how many times the hashing loop should be executed, much like the cost parameter on Blowfish. The default number of rounds is 5000, there is a minimum of 1000 and a maximum of 999,999,999. Any selection of N outside this range will be truncated to the nearest limit.
    CRYPT_SHA512 - SHA-512 hash with a sixteen character salt prefixed with $6$. If the salt string starts with 'rounds=$', the numeric value of N is used to indicate how many times the hashing loop should be executed, much like the cost parameter on Blowfish. The default number of rounds is 5000, there is a minimum of 1000 and a maximum of 999,999,999. Any selection of N outside this range will be truncated to the nearest limit.

Glorious.

If no is the answer, then there is completely no advantage of using bcrypt versus multi hashes with multi salt as I have already written a recurrent function which does exactly the same as bcrypt().

You simply use the_hash_function($data, salt1, salt2, salt3, rounds) and basically what it does is it recurrently repeats


for X number of rounds, each time salting everything again.

Once the hardware becomes more powerful, i can simply increase the number of rounds to Y.

If no is the answer, then there is completely no advantage of using bcrypt versus multi hashes with multi salt as I have already written a recurrent function which does exactly the same as bcrypt().

You simply use the_hash_function($data, salt1, salt2, salt3, rounds) and basically what it does is it recurrently repeats


for X number of rounds, each time salting everything again.

Once the hardware becomes more powerful, i can simply increase the number of rounds to Y.

id assume no, or else it would be pointless to increase round time.

I am a programmer from 14 years, and FYI, i have written from scratch strong cryptography algorithms myself.
So please stop talking bullshit and let's have a real discussion other than "BCRYPT FTW, IF YOU DON'T THINK SO, STFU".

You should be using bcrypt().
Not whatever many rounds of hashing.

Hashing is meant for huge amounts of data (such as files) and is meant to run fast - which means it can be bruteforced fast.

By using bcrypt with a high work factor, logins take one second to process - and bruteforcing takes one second per hash as opposed to 10 billion hashes per second.