# Quantum PRGN against Hard disk Forensics

We can make use of the Qbit to make a random string of bytes then as I have an office laptop and I can do some espionage by copying the files to my local disk from the network share and upload it to some online board.

It Leaves a shadow file if I choose to delete it and or encrypt the file. If forensics is performed then that file can be retrieved in its entirity( best case), partially(most cases), encrypted entirety( rarely), or a sign that the file was attempted to be shredded and implementation may vary from OS to OS and File system to file system.

My proposal is that we expose an online service where we input the remaining size of our harddisk, let's suppose I have a disk size of 2TB and 1.5TB is remaining so I shall download a file with Quantum random numbers of size 1.5TB hence overriding all the memory cell even if the disk firmware is ware balanced it will not be able to preserve the fragments of the previously deleted files as we are filling all the leftover disk space with random quantum numbers.

• What is your question? Do you want to know if your proposal is possible? Jan 10 at 7:28
• Dear @MartinVesely, Yes I would want to know about the feasibility and any ways to implement with any cloud service already available. Jan 10 at 15:07
• You would obtain the same result (i.e. complete deletion of 'residual' information) by just writing a $0$ to every data bit on your harddrive - no randomness needed.
– JSdJ
Jan 11 at 9:33

To erase a HDD with a random numbers generated by quantum computer is in theory possible. Lets imagine you want to generate bit strings of length $$n$$, then you can simply put Hadamard gates on $$n$$ qubits. Such simple circuit prepares equal superposition of all $$n$$ bit long strings. When you put measurement after the Hadamard gates and run the circuit on a quantum computer you will get a random bit string coming from uniform distribution.

However, nowadays there are two main obstacles:

1. A small number of qubits in current quantum processors (as far as I know, IBM offers 63 qubit processor). But this can be easily overcame but producing higher number of shorter bitstrings.

2. Most importantly, you would need to run your circuit many times to produce 1.5 TB of random bits. Since 1.5 TB = 12 Tb and suppose that you are able to produce at 63 bits long stings (on the IBM computer I mentioned above), this will take 190 million of runs. This is possible, however, I do not think that IBM would allow such load of their systems now.

To conclude, yes it is possible but because of small capacity of current quantum computer it is difficult to do so.

Just suggestion: try to use some physical generator of random numbers. They are based on measuring thermal noise. Produced random numbers are really random as in case of quantum computer. No algorithms like linear congruential generator is used.

• There are also some 'Quantum Random Number Generators' available that are not quantum computers, but do provide randomness based on 'quantum mechanics'. See for instance IDQuantique's QRNG.
– JSdJ
Jan 11 at 9:35