Data-at-Rest Encryption in DuckDB

19 hours ago (duckdb.org)

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?

Curious how the indexing of a key is hanlded. I'm not sure if the document already has it (as I don't remember coming across this), but I'm just a bit curious. Will the key being searched for be "encrypted" before a search or will a decryption occur for each block during a search.

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.

  • 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

    • 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.

    • We are in the separate ACL/encryption key bucket. We provide a Bayesian data analytics platform/api for other companies. Each company can have hundreds to thousands of datasets ("indices") each of which has a separate encryption key, and those keys are also stored encrypted with an organizational level key that is rotated daily.

  • 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.

    • I'm more amazed that they released this as part of their open-source offering (not clear from my above comment). Encryption is a standard lever for open-source projects to monetize.

      I run a small company and needed to budget solid amount of chunk of time for next year to dig into improving this component of our system. I respect your perspective around holding high standards, but I do think it's worth getting excited about and celebrating reliable performant software that demonstrates consistent competence.

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

"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

  • How do you use these in practice? Both Python and Go don’t make it easy to link a different variation of SQLite with one of these plugins compiled in. How do you make it work?

    • I don't think SqliteMultipleCiphers can be built into a runtime loadable extension (and the Turso thing is just a copy of it).

      I'm confident that a scheme based on tweakable block cyphers (like Adiantum or AES XTS) could be made into decent runtime loadable extension.

      I implemented such schemes for my Go driver, but Go code is not really ideal to make a runtime loadable extension of (it'd have to be ported to C/Rust/zig).

      https://news.ycombinator.com/item?id=40208800