The scientists in the Vienna research group demonstrated
this concept of blind quantum computing in an experiment:
they performed the first known quantum computation
during which the user’s data stayed perfectly encrypted.
The experimental demonstration used photons, or light
particles, to encode the data. back to the user who can then interpret and utilize them.
Even if the quantum computer or an eavesdropper tries to
read the qubits, they gain no useful information without
knowing the initial state; hence they are “blind.”
The process works in the following manner. The user pre-
pares qubits – the fundamental units of quantum comput-
ers – in a state known only to that user, and sends those
qubits to the quantum computer. The quantum computer
entangles the qubits according to a standard scheme. The
actual computation is measurement-based: simple mea-
surements on qubits implement the processing of quantum
information. The user tailors the measurement instructions
to the particular state of each qubit, and sends them to the
quantum server. The results of the computation are sent According to the analysis done by the National Institute of
Standards and Technology (NIST), the most important uses
of public key cryptography today are for digital signatures
and key establishment. The construction of a large-scale
quantum computer would render many of these public key
cryptosystems insecure. This includes, in particular, sys-
tems based on the difficulty of integer factorization, such as
RSA, as well as ones based on the hardness of the discrete
log problem. Hence, the search for algorithms believed to
be resistant to attacks from both classical and quantum
computers has focused on public key algorithms.
30 | THE DOPPLER |
SPRING 2019
Quantum Safe Encryption