Basically no data is really secure over time, irrespective of encryption. I’ve posted some quantum computing pieces before as this topic is clearly moving from speculation to likely reality.
From the article:
“A recent report from the Global Risk Institute predicted that there is a one in seven chance vital cryptography tools will be rendered useless by 2026, rising to a 50% chance by 2031. In the meantime, hackers and spies can hoover up data encrypted using current approaches and simply wait until quantum computers powerful enough to crack the code have been developed.”
There are plenty of corporate challenges here, and you might also want to think twice about what you choose to back up to the cloud. Assume that any remnant copy of it will (effectively) decrypt in 10-15 years.