Re: [Ntp] ntpv5 requirements

[Harlan Stenn <[e-mail]>]

On 2/13/2023 8:06 AM, Miroslav Lichvar wrote:
> On Thu, Feb 09, 2023 at 05:18:20PM +0000, Doug Arnold wrote:
>> For example: Judah Levine at NIST recently told me that he cannot implement NTS with his current server resources and the number of clients NIST supports.  However, when I told him about TESLA he thought a scheme based on that would be doable, as long as the keys didn’t have to change too often.
> 
> That is interesting as NTS was specifically designed to scale well to
> very large numbers of clients.

I don't recall performance in NTS as being a primary goal of the design.

Sure, it was listed as *a* goal, but the primary goals were around 
"security".

> Is their concern about decryption
> and encryption of NTS-protected NTP packets, or rather TLS in NTS-KE?
 >
> In 2016 they reported they had about 200k requests per second across
> all their servers [1]. Even if it was 100x more today and all clients
> were using NTS, that could still be handled by a dozen of servers with
> multi-core CPUs and AES acceleration. In my tests I get about 200k/s
> per core.

 From what I've heard, NTS key operations take 5-10x the amount of 
compute power beyond what NTP needs.

> NTS-KE traffic is more difficult to predict as it depends on the
> client implementations. I would be curious to see what NTS-NTP to
> NTS-KE request ratio do the well-known NTS providers like Cloudflare
> and Netnod have.
> 
> [1] https://nvlpubs.nist.gov/nistpubs/jres/121/jres.121.003.pdf
> 

-- 
Harlan Stenn <[e-mail]>
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