Re: [PATCH 0/3] Implementation of Ascon-Hash256

[Rusydi H. Makarim]

On 2025-12-16 03:19, Eric Biggers wrote:
> On Mon, Dec 15, 2025 at 02:54:33PM +0700, Rusydi H. Makarim wrote:
> > This patch implements Ascon-Hash256. Ascon-Hash256 is a hash function 
> > as a part
> > 	of the Ascon-Based Lightweight Cryptography Standards for Constrained 
> > Devices,
> > 	published as NIST SP 800-232 
> > (https://csrc.nist.gov/pubs/sp/800/232/final).
> >
> > Signed-off-by: Rusydi H. Makarim <rusydi.makarim@xxxxxxxxxxxxx>
>
> What is the use case for supporting this algorithm in the kernel?  
> Which
> specific kernel subsystem will be using this algorithm, and why?

Ascon is a NIST standard (published in August 2025) for hashing, XOF, 
and AEAD in resource-constrained devices. Since it is a NIST standard, 
akin to AES and SHA-3, it will eventually find its way into the Linux 
kernel. It is only a matter of _when_ it becomes part of the kernel.

> There's a significant maintainence cost to each supported algorithm.  
> So
> if there's no in-kernel user, there's no need to add this.

While no direct in-kernel use as of now, adding this primitive now 
reduces the barrier for future adoption by kernel subsystems. 
Ascon-Hash256 specifically can serve as an alternative hash function to 
SHA-3 or Blake for existing use cases on devices that require more 
lightweight hashing.

The implementation of the standard starts with Ascon-Hash256 and is 
intentionally kept minimal to gather initial feedback. The final goal is 
to implement the complete NIST SP 800-232 in the kernel, which also 
includes Ascon-XOF128, Ascon-CXOF128, and Ascon-AEAD128.

> - Eric

Best,
Rusydi