takes on value 0. Instead, if there is a conflict, VALIDITY still
reflects the key's validity (values: 1-4).
+ SUMMARY values use the euclidean distance (m = sqrt(a² + b²)) rather
+ then the sum of the magnitudes (m = a + b) to ensure a balance between
+ verified signatures and encrypted messages.
+
+ Values are calculated based on the number of days where a key was used
+ for verifying a signature or to encrypt to it.
+ The ranges for the values are:
+
+ - 1 :: signature_days + encryption_days == 0
+ - 2 :: 1 <= sqrt(signature_days² + encryption_days²) < 8
+ - 3 :: 8 <= sqrt(signature_days² + encryption_days²) < 42
+ - 4 :: sqrt(signature_days² + encryption_days²) >= 42
+
SIGN-COUNT and ENCRYPTION-COUNT are the number of messages that we
have seen that have been signed by this key / encryption to this
key.