[dns-operations] Multiple DS DNSSEC validation

[Stephane Bortzmeyer]

On Tue, Jul 11, 2017 at 12:08:54AM -0300,
 Rubens Kuhl <rubensk at nic.br> wrote 
 a message of 25 lines which said:

> it just happens that depending on name server an specific key will
> be used, since each one only has its own private key, although
> knowing the public keys of all 3.

It is used in Yeti
<https://github.com/BII-Lab/Yeti-Project/blob/master/doc/Report-MZSK.md>
and basically works.