+# FIXME: make tables of relevant identifiers: digest algorithms,
+# ciphers, asymmetric crypto, packet types, subpacket types, signature
+# types. As these are created, replace the opaque numbers below with
+# semantically-meaningful code.
+
+# see RFC 4880 section 5.2.3.21
+my $usage_flags = { certify => 0x01,
+ sign => 0x02,
+ encrypt_comms => 0x04,
+ encrypt_storage => 0x08,
+ encrypt => 0x0c, ## both comms and storage
+ split => 0x10, # the private key is split via secret sharing
+ authenticate => 0x20,
+ shared => 0x80, # more than one person holds the entire private key
+ };
+
+