No encryption, none needed.
The bank provides a room inside the actual vault (yup - super thick walls, huge heavy door, time-lock, just like in those bank heist movies).
My little drawer has its own key and access.
Worrying about a thief penetrating the vault, knowing which drawer is mine, and bothering to drill out the lock to steal the contents of my drawer without getting caught is simply one of those things that doesn’t keep me up at night.
Where are you getting 28TB drives for $400? Looking at local options for me, including Amazon (Australia), I can find nothing anywhere close to that price. In fact nothing less than double that.
Here’s one:
Amazon typically. There are a bunch of reputable drive manufacturers that have drives in the 20-28TB range that are very reasonable.
I use the 20T and 24T version of these.
Usually, the slightly-less-than-largest has the better price/tbit deal.
I also buy most of my big-ticket Apple items from B&H. Underappreciated great place to buy all Apple gear.
They are reputable, fully authorized Apple resellers and stock multiple configurations, not just the popular “best seller” standard retail models.
They don’t have immediate availability for new products, but I typically don’t buy laptops or desktops so quick.
I especially like their “we pay the tax” deal. For me, CA state sales tax is close to 10%, no other place to buy Apple where you can get that much off a purchase all the time.
It does take “playing the game” of getting their private-label credit card and then having the discipline to pay it off immediately after each purchase, but over the past few years I’ve saved hundreds, if not a thousand dollars on expensive computer, camera, and video equipment. (Mac Studio, Apple Studio Display, Apple Watches, Mac Book Air, etc.)
Also not well-known, they have a lot of computer stuff one might typically go to Amazon or other places for too - routers, networking gear, cables, ssd’s, etc.
They’ve definitely been in business for a long time. I purchased my 35 mm Nikon cameras and lenses from them in the early 80s.
I try to avoid Amazon for electronics, and B&H is my first stop when electronics shopping.
Except when I can get the item that I want from my local camera shop!
“Buy Local” if you can is still a good idea. 
I agree 100%. Alas, my closest shop is now 2 hours away, and in another state. 
But I did buy my last camera body there!
Most local camera shops in my area have closed. I really like my iPhone camera. But unintended consequences have left me with no local shops.
Sadly, for some things, it is getting harder to buy local. I’m fortunate to still have two local camera shops. One of them is nothing special so I don’t go there anymore.
But National Camera Exchange, in the delightfully named Minneapolis suburb of Golden Valley, is great. I like shopping there. It still does a lot of business and has many knowledgeable and friendly people behind their long counter that enjoy “talking camera” with me. They have all the new gear, but buy and sell used camera equipment as well!
I see a story arc here. OK, so let’s look past the fact that every single drive I have had fail in the last 10+ years (no exaggeration, I have the pile to prove it) has been a Seagate.
Nobody local stocks these. Mevet’s closest shop is 2 hours away? I have a much more local electronics shop that doesn’t stock anything this cheap.
Should I buy from Amazon? At least there is an Amazon Australia and in this case they will ship it to New Zealand. Often they won’t. Do I trust Amazon? Probably. But it’s sold by a third party. Do I trust them? Ehhhhh. Maybe not?
Still… B&H are the trustworthy players, right?
I do, too, except it often ends up being a HUGE markup for me. Surprisingly, to me, this one seems quite reasonable. The net price to me, from B&H is USD$489. Or ~NZD$820.
That is surprisingly affordable, considering the only equivalents here are more like NZD$1300 and up. But it’s still a Seagate and it’s still just one ‘click’ away from being useless, at which point you have to buy again. Also, it’s not a bare drive. I trust Seagate’s interfaces even less. (Again, from experience). Warranty, you say? It is generally completely impractical unless I buy local. See above.
Fortunately I don’t need a 28TB hard drive because I can trust in Backblaze to keep their hard drives healthy as long as I keep paying them. Yes that is a ‘dreaded’ subscription, but the value is that it is very highly unlikely it will ever go ‘click’.
But the moral of the story here is that “there are 28TB hard drives available for under $400” is a localised statement. Yes, if…
Closest camera shop.
Update: As it turns out, B&H’s store in NYC is actually closer. 
True. And by way of reference for us the nearest place with an electronics store is a full days drive to Denver across the mountains or a full days drive to Salt Lake City. We buy lots of stuff off Amazon because there are no local stores. I’ve had decent luck with Seagate but usually prefer Western Digital drives and that’s what we use in our NAS systems and what I use too store my backups.
I can’t speak to WD drives versus Seagate, but due to the totally unethical business practices of WD when they bought Sandisk and sold knowingly failure-prone SSDs and their terrible customer service, I refuse to buy anything from WD.
Unethical behavior - when the problem became known and publicized, instead of taking the drives off the market, they pushed heavily sales promotions and discounts across all their online and dealer channels trying to clear out all the inventory and keep selling to suckers (aka consumers) while stonewalling all problem reports to customer service.
Anecdotal: My neighbor works for an Enterprise disk drive company (they sell mainly to corporations and data centers) and she confirmed that whenever her paths crossed with WD people they were crass, arrogant, greedy, and unethical in their business dealings.
You can Google. many. YouTubers that have covered this, but I think a class action lawsuit hold even more credibility:
I did end up buying a bunch of SSD drives during that time. Several failed dramatically. But I had no issues at all with getting them totally replaced at no charge at all. So for me at least they redeemed themselves enough to continue buying drives from them simply because they had no issues with providing a replacement for any drive malfunction I’ve ever had. I’ve had 2 of their spinning drives fail and one was within a few weeks of being out of warranty. It was replaced with a brand new one with no hassles.I rotate the drives, newest ones get slotted into the nightly backups and time machine functions. As the drives age they move to the monthly and archive backups and when out of warranty they go to my husband who uses them like high capacity thumb drives with totally replaceable stuff until they die. Which all drives do eventually.