pie in sky suites - long lived public key pairs for persistent identity

[coderman]

use case is long term (decade+) identity rather than privacy or
session authorization.

eternity key signs working keys tuned for speed with limited secret
life span (month+).  working keys are used for secret exchange and any
other temporal purpose.

you may use any algorithms desired; what do you pick?


Curve3617+NTRU eternity key
Curve25519 working keys
ChaCha20+Poly1305-AES for sym./mac
?


this assumes key agility by signing working keys with all eternity
keys, and promoting un-broken suites to working suites as needed.  you
cannot retro-actively add new suites to eternity keys; these must be
selected and generated extremely conservatively.

other questions:
- would you include another public key crypto system with the above?
(if so, why?)
- does GGH signature scheme avoid patent mine fields? (like NTRU patents)
- is it true that NSA does not use any public key scheme, nor AES, for
long term secrets?
- are you relieved NSA has only a modest effort aimed at keeping an
eye on quantum cryptanalysis efforts in academia and other nations?


best regards,