The single call the protocol runner makes on a site. Implementations
return the site's contribution already encrypted, using the
public parameters the site was given when it was configured, so an
individual site's cleartext contribution never reaches the
aggregator — that is the property the whole protocol rests on, and
master_aggregate() refuses a reply that is neither an encrypted
value under this protocol's key nor NA.
Arguments
- site
a LocalSite, or a user-defined subclass of RemoteSite.
- ...
method-specific arguments; both built-in methods take
theta, the parameter value being queried.
Value
an encrypted contribution, of whatever type the site's own
public parameters imply, or NA if theta is non-evaluable here.
Details
The computation is entirely local. A site needs nothing at call time
beyond theta, its own data, and what it already holds.
The only permitted plaintext reply is NA, signaling that theta
is non-evaluable at this site; CKKS has no representation for it, so
it cannot be encrypted. A site that cannot be reached must signal
site_unavailable() instead of returning NA.
See also
RemoteSite for the contract a remote implementation must honor.