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Section 2.2: The manual key management for long-term session keys
meets the last criteria in this section:
The scale of each deployment is very limited.
Ideally, each long-term key in DTLS is shared only between one server
and one client. Each client-server pair shares a unique key, and those
keys are (ideally) not re-used across multiple client-server pairs.
There aren't many deployments that are smaller scale than two parties.
gwz> I don't think that by "deployment" they mean how many parties share a key
gwz> ;-); more like how many NASs to a server (which can be in the thousands).
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