I thought it was already fairly well established that symmetric encryption is not something that a quantum computer could potentially crack, only asymmetric encryption is theoretically possible due to its use of a prime order field.

Shor’s algorithm is a quantum algorithm for finding the prime factors of an integer. It was developed in 1994 by the American mathematician Peter Shor.[1][2] It is one of the few known quantum algorithms with compelling potential applications and strong evidence of superpolynomial speedup compared to best known classical (non-quantum) algorithms

a quantum computer with a sufficient number of qubits could operate without succumbing to quantum noise and other quantum-decoherence phenomena, then Shor’s algorithm could be used to break public-key cryptography schemes, such as

• The RSA scheme
• The Finite Field Diffie-Hellman key exchange
• The Elliptic Curve Diffie-Hellman key exchange

Moreover:

The largest number reliably factored by Shor’s algorithm is 21 which was factored in 2012 (ie faster than a regular computer, the much higher records like 48 bit utilized pre and post processing and was faster on a regular computer).

Even if we go with the assumption that the military is 10 years ahead in technology and can factor 221 with Shor’s, that’s still nowhere near enough to break RSA. Much more efficient to attack all the systemic flaws in RSA, hence why 1024 is no longer considered secure, 2048 is assumed to be breakable by any 3 letter agency, 4096 is assumed to be safe (for now), but mostly the latest and greatest is elliptical ECDSA/Ed25519 (of which NIST has been accused of rigging ECDSA for easier cracking lol).