[Security Engineering and Cryptography] Which of the following is the main reason quantum computing advancements are leading companies and countries to deploy new encryption algorithms?

The primary cryptographic threat from quantum computing stems from Shor's algorithm. This algorithm can efficiently solve the integer factorization and discrete logarithm problems, which are computationally infeasible for classical computers. Most of today's widely used public-key cryptography, including RSA and Elliptic Curve Cryptography (ECC), relies on the difficulty of these problems. A sufficiently powerful quantum computer could break this encryption, compromising vast amounts of secured data and communications. This imminent vulnerability is the main reason for the global effort, led by organizations like NIST, to develop and standardize new, quantum-resistant encryption algorithms.

B. Zero Trust is a strategic security model, and while homomorphic encryption is a useful technology, it is not a mandatory component, nor is it the primary driver for quantum-resistant algorithms.
C. The challenge that Perfect Forward Secrecy (PFS) poses to traffic inspection is a current issue with classical cryptography and network monitoring, not a new problem created by quantum computing.
D. Quantum computers are powerful computational devices designed to solve complex mathematical problems; they do not provide a new or enhanced capability for capturing network traffic in real time.

1. National Institute of Standards and Technology (NIST). (2016). Report on Post-Quantum Cryptography (NISTIR 8105). "Shor’s algorithm can be used to efficiently find the prime factors of a large integer, which would break any cryptosystem based on the factoring problem, such as RSA. Shor’s algorithm can also be used to solve the discrete logarithm problem... such as DSA and ECDSA." (Section 2.2, Page 3). https://nvlpubs.nist.gov/nistpubs/ir/2016/NIST.IR.8105.pdf

2. Bernstein, D. J., & Lange, T. (2017). Post-quantum cryptography. Nature, 549(7671), 188–194. "A sufficiently large-scale quantum computer will be able to use Shor’s algorithm to break all of the public-key cryptography that is currently in widespread use." (Page 188, Abstract). https://doi.org/10.1038/nature23461

3. Shor, P. W. (1997). Polynomial-Time Algorithms for Prime Factorization and Discrete Logarithms on a Quantum Computer. SIAM Journal on Computing, 26(5), 1484-1509. This foundational paper details the algorithm that poses the threat to public-key systems based on these two mathematical problems. (Section 1, Introduction). https://doi.org/10.1137/s0097539795293172