My attempt to implement hash function somewhat similar to sha-256.
Clone the project
git clone https://github.com/tmneth/hash-generator.git
# to automatically load submodules, you can use –recurse-submodules switch
git clone --recurse-submodules https://github.com/tmneth/hash-generator.gitInitialise and update submodules to use existing hash functions
git submodule init
git submodule update
Compile the files
g++ src/*.cpp lib/hash-library/{sha256,md5,sha1,keccak}.cpp -o 'main' && ./main
Once compiled, user will be presented with the following options:
Please use one of the following flags:
-h, --help: Show this help message
-f, --file: Hash a file
-s, --string: Hash an input string
-t, --tests: Perform tests
--salt: Add salt to hash
Example:
# hash a file
./main -f empty.txt
# hash a string
./main -s "hello world"
# load the tests
./main -t*Note, for a salt to be used, it has to be passed as the first command line argument
./main --salt "something" -s "hello world"
To understand how the algorithm works check out step-by-step hash of “hello world”
For the test purposes 7 different text files were created. Every single file was hashed twice, hexes were compared.
Hashing twice file: letter.txt; Word size: 64
Hash (1): c56ebd88c9afd0981201c4de665372aad244bbf8861f54743fecd1d484caff2c
Hash (2): c56ebd88c9afd0981201c4de665372aad244bbf8861f54743fecd1d484caff2c
Hashes are: identical
Hashing twice file: char.txt; Word size: 64
Hash (1): 509edaaa536b19e8c44a4bd484f27358f05f4c70fb51ce900a8f11388be4e8d4
Hash (2): 509edaaa536b19e8c44a4bd484f27358f05f4c70fb51ce900a8f11388be4e8d4
Hashes are: identical
Hashing twice file: rand_1000_1.txt; Word size: 64
Hash (1): be5414a42b887e3026f76784ab760408f4515fd4b14859b0774f0d588fb08098
Hash (2): be5414a42b887e3026f76784ab760408f4515fd4b14859b0774f0d588fb08098
Hashes are: identical
Hashing twice file: rand_1000_2.txt; Word size: 64
Hash (1): 6dae59dcf00227f01114ee783aa083e0c02ba9b0ae91d82033e42608e1d33678
Hash (2): 6dae59dcf00227f01114ee783aa083e0c02ba9b0ae91d82033e42608e1d33678
Hashes are: identical
Hashing twice file: sim_1500_1.txt; Word size: 64
Hash (1): 62610d2829307e5c2f051b700ad57dd85e5e2fe05297545434d52fb4e25b37d0
Hash (2): 62610d2829307e5c2f051b700ad57dd85e5e2fe05297545434d52fb4e25b37d0
Hashes are: identical
Hashing twice file: sim_1500_2.txt; Word size: 64
Hash (1): 5e31f454f557c94c268adbe892b049f0d20e2e98aa9892e44f348708e1292800
Hash (2): 5e31f454f557c94c268adbe892b049f0d20e2e98aa9892e44f348708e1292800
Hashes are: identical
Hashing twice file: empty.txt; Word size: 64
Hash (1): 0152fb74025769d049710ea4f8f46cbcb539d6b88fdd309866860174ecc54ea0
Hash (2): 0152fb74025769d049710ea4f8f46cbcb539d6b88fdd309866860174ecc54ea0
Hashes are: identical
Conclusion: hashing algorithm is deterministic.
To test execution time, it was measured how much time it takes for the function to hash 1,2,4,8...512 lines from file konstitucija.txt - overall time grows linearly. (100 hashing rounds were performed & the average time was calculated).
Time complexity of the hash function is O(n).
| Lines | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 |
|---|---|---|---|---|---|---|---|---|---|---|
| Time | 0.000007s. | 0.000013s. | 0.000028s. | 0.000053s. | 0.000109s. | 0.000210s. | 0.000432s. | 0.000862s. | 0.001735s. | 0.003466s. |
For this test, pairs of randomly generated strings were hashed and compared (25000 pairs of 10, 100, 500, 1000 character long, randomly generated strings).
No collisions were found.
After hashing, 25000 pairs of 10, 100, 500, 1000 character longs strings, that differ only by one character, following results were achieved:
Avg difference (hex): 91.48%
Avg difference (bit): 32.43%
Min difference (hex): 73.44%
Min difference (bit): 22.66%
Max difference (hex): 100.00%
Max difference (bit): 42.97%
Overall, MYSHA average difference hexwise and bitwise was the smallest compared to other algorithms.
| avg (hex) | avg (bit) | min (hex) | min (bit) | max (hex) | max (bit) | |
|---|---|---|---|---|---|---|
| MYSHA | 91.48% | 32.43% | 73.44% | 22.66% | 100.00% | 42.97% |
| SHA256 | 93.74% | 33.01% | 76.56% | 23.63% | 100.00% | 42.77% |
| MD5 | 93.73% | 33.01% | 68.75% | 19.53% | 100.00% | 45.70% |
| SHA1 | 93.75% | 33.01% | 70.00% | 21.25% | 100.00% | 44.06% |
| KECCAK | 93.74% | 33.01% | 76.56% | 23.83% | 100.00% | 43.36% |
To test execution time, it was measured how much time it takes for every function to hash 1,2,4,8...512 lines from file konstitucija.txt. (100 hashing rounds were performed & the average time was calculated). Overall, MYSHA performed as the second-slowest function in this test, being only faster than KECCAK. Meanwhile, MD5 and SHA1 were the fastest ones.
To reduce chances of guessing the input, unique salt can be added to each string before its hashing. To test how salt mutates output, previously used 7 files were hashed with and without adding salt, which was randomly generated. As you can see, salt drastically changes the output.
Hashing twice file: letter.txt; Word size: 64
Hash (original): c56ebd88c9afd0981201c4de665372aad244bbf8861f54743fecd1d484caff2c
Hash (salted): 0709daf4907a61dc777b043271c28b7c23543c80072da7040d479398e1a437ac
Hashing twice file: char.txt; Word size: 64
Hash (original): 509edaaa536b19e8c44a4bd484f27358f05f4c70fb51ce900a8f11388be4e8d4
Hash (salted): ee128ec4ef719ad865329286e41ace2ecc2c0ca8b1cb68bcd423bbbc006251cc
Hashing twice file: rand_1000_1.txt; Word size: 64
Hash (original): be5414a42b887e3026f76784ab760408f4515fd4b14859b0774f0d588fb08098
Hash (salted): 390571101ba2db68b986f5308aab2c7c730bf9f0df54abe08f215dd400128e68
Hashing twice file: rand_1000_2.txt; Word size: 64
Hash (original): 6dae59dcf00227f01114ee783aa083e0c02ba9b0ae91d82033e42608e1d33678
Hash (salted): 3dae09f0cea1c65827cffcd4c45b7b5c2abf0018e466d9687ea53d284d0cd70c
Hashing twice file: sim_1500_1.txt; Word size: 64
Hash (original): 62610d2829307e5c2f051b700ad57dd85e5e2fe05297545434d52fb4e25b37d0
Hash (salted): 1a0ceeb8e03ef40834b9255c5936465c7316a290cb795c1c3dd70a0c0eda180c
Hashing twice file: sim_1500_2.txt; Word size: 64
Hash (original): 5e31f454f557c94c268adbe892b049f0d20e2e98aa9892e44f348708e1292800
Hash (salted): 9fba34903351715c04ef39546efeb5b4b932d888838fea0c6b71c11cf34653dc
Hashing twice file: empty.txt; Word size: 64
Hash (original): 0152fb74025769d049710ea4f8f46cbcb539d6b88fdd309866860174ecc54ea0
Hash (salted): e4775a6c1d9bda18e5c8c454d2b71454df158320c5d0e9b4c5700870ec014824