Data-at-Rest Encryption in DuckDB
12 comments
·November 20, 2025glenjamin
Other than motherduck, is anyone aware of any good models for running multi-user cloud-based duckdb?
ie. Running it like a normal database, and getting to take advantage of all of its goodies
mritchie712
For pure duckdb, you can put an Arrow Flight server in front of duckdb[0] or use the httpserver extension[1].
Where you store the .duckdb file will make a big difference in performance (e.g. S3 vs. Elastic File System).
But I'd take a good look at ducklake as a better multiplayer option. If you store `.parquet` files in blob storage, it will be slower than `.duckdb` on EFS, but if you have largish data, EFS gets expensive.
We[2] use DuckLake in our product and we've found a few ways to mitigate the performance hit. For example, we write all data into ducklake in blog storage, then create analytics tables and store them on faster storage (e.g. GCP Filestore). You can have multiple storage methods in the same DuckLake catalog, so this works nicely.
0 - https://www.definite.app/blog/duck-takes-flight
kianN
I’m just continually amazed by the DuckDB team. We had built out a naive solution with OpenSSL to encrypt duckdb files, but that lead to a 2x runtime cost for first time queries and used up a lot of ram because we were encrypting/decrypting the entire file all at once. It seems like because DuckDB is encrypting at the page level and leveraging modern processors native AES operations, they are able to perform read/writes at practically no cost.
PunchyHamster
Why not just LUKS ? Kernel level, leverages acceleration, transparent to anything you run on top of it.
DB encryption is useful if you have multiple things that need separate ACL and encryption keys but if it is one app one DB there is no need for it
beala
From the article:
> This allows for some interesting new deployment models for DuckDB, for example, we could now put an encrypted DuckDB database file on a Content Delivery Network (CDN). A fleet of DuckDB instances could attach to this file read-only using the decryption key. This elegantly allows efficient distribution of private background data in a similar way like encrypted Parquet files, but of course with many more features like multi-table storage. When using DuckDB with encrypted storage, we can also simplify threat modeling when – for example – using DuckDB on cloud providers. While in the past access to DuckDB storage would have been enough to leak data, we can now relax paranoia regarding storage a little, especially since temporary files and WAL are also encrypted.
letmetweakit
I believe it's also to protect against the occasionally "lost" DB file.
notorious_pgb
With respect, none of this sounds like "amazing" work on DuckDB's part. It's not bad work, either! It's competent work.
Comparing it to a naive approach (encrypting an entire database file in a single shot and loading it all into memory at once) is always going to make competent work seem "amazing".
I say this not to shit on DuckDB (I see no reason to shit on them); rather, I think it's important that we as professionals have realistic standards that we expect _ourselves_ to hit. Work we view as "amazing" is work we allow ourselves not to be able to replicate. But this is not in that category, and therefore, you should hold yourself to the same standard.
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jedisct1
"Sqlite [...] encryption extension is a $2000 add-on".
SqliteMultipleCiphers has been around for ages and is free https://utelle.github.io/SQLite3MultipleCiphers/
And Turso Database supports encryption out of the box: https://docs.turso.tech/tursodb/encryption
null
AES-GCM sensitivity to nonce reuse is a tricky implementation detail. Here they acknowledge it but then don’t share their solution - and in fact the header contains 16 bytes for the nonce instead of the expected 12 bytes and they do not share what bytes are random. Did I miss something, anyone know?