Why Key Rotation

-
/via https://bit.ly/2HKytRW
If you have encrypted data up there in the cloud (•) you’ve probably run across key rotation. It’s good practice — very good practice — and exists for some fairly straightforward reasons
  1. • Encryption stales. Sometimes it’s just a matter of time (DES was awesome in 1977. Now, not so much). So if your encryption algorithm can be broken in N years, you probably want to rotate it in some period smaller than N, no?
    And yeah, N isn’t necessarily “heat death of the universe” because you’re using 4096-bit keys. Things change — key leaks, quantum encryption, NSA loopholes, whatever. The safe thing to do is just rotate your signing key — and, potentially, the algorithm too !— every so often (••)
  • • Keys Leak. It happens, and for a host of reasons, ranging from “whyTF did you write it down on a Post-it?” to state-actors. In either case, keys do leak. The safe thing to do is rotate your encryption key every so often, so that when keys do get compromised, the amount of data that you lost isn’t, well, Everything.
  • • Straight up attacks. For many (most?) encryption algorithms, the more data you gather, the easier it is to break. A prominent example is AES GSM, that loses it’s protection-fu if more than 64GB of data is encrypted with the same key (••). Key rotation, FTW!
So yeah, the bottom line is that key rotation is A Good Thing.
(•) Or even down in your own system. Basically, this applies to any encrypted data
(••) See NIST SP 800–38D section 5.2.1.1 for details on AES GCM, and the 64GB fun.

Comments

Post a Comment

Popular posts from this blog

Erlang, Binaries, and Garbage Collection (Sigh)

-
Image
The nice thing about garbage-collection is that it is makes memory management absolutely transparent to you Of course, the above is true right up to the point when it stops being transparent, at which point it does a phase change from nice to clusterf**k of biblical proportions .  There are entire posts, books, and suicide notes that have been written about this, and I have no great desire to add to them, save with the minor comment that paranoia about garbage-collection is still justified , albeit only in the edge-cases for most people. That said, I'll give you that Erlang GC is in many ways much, much better positioned in this regard than, oh, Java, but it still rears up and bites you in the butt when you least expect it. ( More information about Erlang's GC vis-a-vis Java here , and Jesper's truly excellent description of Erlang's GC here ).  A story from the past should serve to illustrate this. Once upon a time, in a magical land far far away - well, Her...
Read more

Spot The Difference — Deep Learning Edition

-
Image
You’ve played  Spot The Difference  at some point, right? (Of course you did. We  all  did  ). Think about what you actually did when you were trying to Spot The Difference — in fact, just do it again with SpongeBob juggling above. You’re probably doing something like 1. Quick glance to the left. 2. Quick glance to the right 3. “ Spatula on the left. Wonder if there is one on the right? ” 4. “ Yup, there is. Sriracha on the right. Is that on the left? ” 5. “ Nope! It’s a ketchup bottle on the left! And there is nothing on the plate below it! ” etc. To summarize, what you’re basically doing is looking at each image alternately, identifying objects in each image, and trying to find the same object in the other image. As it turns out, what most Deep Learning systems do is something quite different. They basically do something like this 1. Figure out everything in the first image (“ ketchup bottle at 1 o-clock, empty plate at 3 o-clock, spatula at 1...
Read more