Here are the encrypted file to use on the factory D-Link web UI directly: MediaFire (I think link is live for 14 days?) and Anonym File (they say it's indefinite, but who knows)
How I generated it, using factory image on firmware selector and s-2's tool:
$ ./dlink-sge-image DIR-853 ~/Downloads/openwrt-23.05.0-ramips-mt7621-dlink_dir-853-a3-squashfs-factory.bin ../openwrt-23.05.0-ramips-mt7621-dlink_dir-853-a3-squashfs-factory_enc.bin
vendor_key: c05fbf1936c99429ce2a0781f08d6ad8
payload_length_before: 9568256
digest_before: bd56cd7db4b3c8cae52eed13f0a63168eb5fc0796c51d3564a7bb4525cafff42f152081047ae9bdc46f5d5784f41cca5d7971f94229b2af1af93b54b007f2bdb
digest_vendor: 8aee6af703f63414a5487b94999298f7d6bc14200b755213619d3255890d73591aa1348d320b92aef306059168e5d7dfcac4be601d364efadc0c430d98c274f1
digest_post: 5b52bb826b6146450f8747b59fac34ec72924a80ef7f0365c0e73ddab49fd5b1ca5f98cc21d5ce566aebb28b2d3686a06342d72bc1449fb648650be3aa0b2818
signed before:
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
signed post:
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
Apparently s-2's patch to the firmware-utils got merged, so maybe the images on firmware selector will already be available in its encrypted form. But until then, you can use the links here to get it without having to build the tools yourself.