ID hashing and Obfuscation using Knuth's Algorithm for C++
You could use it if you need your ids to consist of only numbers. It's based on Knuth's integer hash method and produces obfuscated integer ids.
This realization doesn't work with big-integers, max id should be <= INT_MAX or 2147483647.
CI and Platforms: microsoft/vcpkg#22025
Please just use vcpkg to build this library:
# Windows
git clone https://github.com/microsoft/vcpkg
cd vcpkg
.\bootstrap-vcpkg.bat
.\vcpkg.exe install optimus-cpp
# Unix
git clone https://github.com/microsoft/vcpkg
cd vcpkg
./bootstrap-vcpkg.sh
./vcpkg install optimus-cpp- Calculate
Prime,ModInverseandRandom. All values should be <= INT_MAX. Primeshould be (2147483647). You could take Prime there: http://primes.utm.edu/lists/small/millions/- Calculate
ModInversefor your prime usingOptimus::calcModInverse(2147483647)- this is slow operation so do it once and then save value. - Generate any
Randomyou want - Store those 3 values and then load and use them for create instance of Optimus
- Use generated numbers in the code like this:
#include <iostream>
#include "src/optimus.h"
int main(int argc, char *argv[])
{
std::srand(std::time(nullptr));
// all values <= INT_MAX
uint64 prime = 334214467;
uint64 modInverse = 734363499; // or slow: `uint64 modInverse = Optimus::calcModInverse(prime);`
uint64 random = 763294573; // or `uint64 random = std::rand();`
Optimus optimus(prime, modInverse, random);
if (!optimus.isValid()) {
std::cout << optimus.errorString() << std::endl;
return 1;
}
std::cout << optimus.prime() << " "
<< optimus.modInverse() << " "
<< optimus.random() << std::endl;
for (int i = 1; i < 50; ++i) {
uint64 myId = std::rand();
uint64 encoded = optimus.encode(myId);
uint64 decoded = optimus.decode(encoded);
std::cout.width(7);
std::cout << myId;
std::cout.width(7);
std::cout << decoded;
std::cout.width(12);
std::cout << encoded;
std::cout.width(2);
std::cout << (myId == decoded) << std::endl;
}
return 0;
}Sample output:
334214467 734363499 763294573
1490 1490 1553599643 1
15533 15533 431735082 1
32387 32387 430589988 1
12346 12346 404574787 1
30236 30236 2116699705 1
4436 4436 488513425 1
16199 16199 713306616 1
9225 9225 1975007286 1
8612 8612 136524417 1
32287 32287 1103044208 1
7676 7676 1660024729 1
16109 16109 711195242 1
14641 14641 1711763390 1
22285 22285 820972042 1
11185 11185 1880385342 1
26247 26247 1190902584 1
369 369 465483518 1
11617 11617 1448248846 1
22197 22197 1777686834 1
10690 10690 1977214123 1
52 52 647897841 1
6145 6145 26676782 1
8545 8545 1137943054 1
27736 27736 1677746277 1
2520 2520 893303013 1
23324 23324 1514690361 1
15161 15161 1866416006 1
27545 27545 1104979302 1
17156 17156 761376097 1
13071 13071 848626816 1
12340 12340 279155441 1
104 104 985616469 1
27290 27290 967195427 1
18058 18058 501152627 1
8791 8791 1045662888 1
17030 17030 526570623 1
32742 32742 2043667551 1
1006 1006 1698479655 1
16776 16776 1128316405 1
28947 28947 687863188 1
6428 6428 520465721 1
28154 28154 2099411203 1
30114 30114 2021564427 1
17489 17489 1153750366 1
32257 32257 979131438 1
7079 7079 2006957272 1
28357 28357 825996770 1
3244 3244 1134698089 1
23272 23272 1177231829 1
There are also PHP (+big numbers based on GMP) (https://github.com/jenssegers/optimus) and Go (also INT_MAX) (https://github.com/pjebs/optimus-go) implementations.
Mainly optimus-cpp lib is just a simple port of Go realization.
Another popular solution is http://hashids.org/, but it provides string ids like [A-Za-z0-9].