I need to test CSPRNG using ENT (http://www.fourmilab.ch/random/). I produced random stream from the generator and stored it in a text file as a sequence of 0s and 1s. I've tried different samples but all of them have failed. To check whether I'm performing the test correctly or not, I look on the internet for a pretested random bit sequence and it has failed as well. Do you think the issue is with the tool or with the form of the input to the tool?
I mean it failed to pass the randomness tests including Chi square, arithmetic mean, monte carlo and correlation; all indicate that the two sequences of bits is not random.
I've check ent documentation and I couldn't find anything regarding input format. the parameter -b means ent will process the stream bit by bit.
I used a sample of 500,000 bits.
How are generating the sample of random sequence ? This is a challenging job. This is similar to generating a one time pad. By definition, the bit pattern will never repeat in one time pad.
You may use any bit stream generator similar to the one used in stream ciphers. Secondly, you may increase the bit sequence length.
Thank you Reddy. We already generate the random stream using several entropy sources. The issue was with using ENT to test randomness of that stream. We found that it is not possible to feed ENT with 0s and 1s from a text file. The sequence should be converted to a binary file which then can be used as input to ENT. Now part of the issues is solved.
Mr. Ja'far i want test the random stream using ENT but i don't know how to check it, shall u please give some suggestions to test it.
you can use Matlab easily
%MATLAB random number generator 8 bits have maximum value of 2^8=256
randomNumbers = fix(rand(1,256)*256);
randomNumbers = uint8(fix(randomNumbers));
%save data as a binary file
FID = fopen('rn.bin','w');
count = fwrite(FID, randomNumbers)
fclose(FID);
-------------------------
In ENT program use the following commands in the console
ent.exe -b rn.bin
and
ent.exe -c rn.bin
I am having the same issue as Ja'far, i have a bitstream of 50*10^6 length that passes the nist tests but has issues with the ENT test, so i assume the problem is with how the file is read.
Say my bitstream is stream=[1 0 1 0 0 1...]
I use the code in Matlab to write the bitstream into a binary file
FID = fopen('test.bin','w');
fprintf(FID,'%1d\n', stream)
fclose(FID);
But the ENT test gives bad results when i run ./ent -b test.bin
Is this an issue with how i save the data? Any help is appreciated
the f=[1 0 1 0...] could be strings or numbers. Check the variable using who keyword in Matlab
whos f
If f is string, then you need to convert it to numbers as uint8
Can you help me how to run the example present in ENT program in console so that I will give me the result
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