Re: [Proposal] Table-level Transparent Data Encryption (TDE) and Key Management Service (KMS)

On Fri, Jul 12, 2019 at 07:26:21AM -0400, Sehrope Sarkuni wrote:
> On Thu, Jul 11, 2019 at 9:05 PM Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> >
> > On Thu, Jul 11, 2019 at 08:41:52PM -0400, Joe Conway wrote:
> > > I vote for AES 256 rather than 128.
> >
> > Why? This page seems to think 128 is sufficient:
> >
> > https://crypto.stackexchange.com/questions/20/what-are-the-practical-differences-between-256-bit-192-bit-and-128-bit-aes-enc
> >
> > For practical purposes, 128-bit keys are sufficient to ensure security.
> > The larger key sizes exist mostly to satisfy some US military
> > regulations which call for the existence of several distinct "security
> > levels", regardless of whether breaking the lowest level is already far
> > beyond existing technology.
> >
> > We might need to run some benchmarks to determine the overhead of going
> > to AES256, because I am unclear of the security value.
>
> If the algorithm and key size is not going to be configurable then
> better to lean toward the larger size, especially given the desire for
> future proofing against standards evolution and potential for the
> encrypted data to be very long lived. NIST recommends AES-128 or
> higher but there are other publications that recommend AES-256 for
> long term usage:
>
> NIST - 2019 : Recommends AES-128, AES-192, or AES-256.
> https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-131Ar2.pdf
>
> NSA - 2016 : Recommends AES-256 for future quantum resistance.
> https://apps.nsa.gov/iaarchive/library/ia-guidance/ia-solutions-for-classified/algorithm-guidance/cnsa-suite-and-quantum-computing-faq.cfm
>
> ECRYPT - 2015 - Recommends AES-256 for future quantum resistance.
> https://www.ecrypt.eu.org/csa/documents/PQC-whitepaper.pdf
>
> ECRYPT - 2018 - Recommends AES-256 for long term use.
> https://www.ecrypt.eu.org/csa/documents/D5.4-FinalAlgKeySizeProt.pdf

Oh, interesting. Let's see what performance tests with the database
show.

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Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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