NIP-41 "HD" Key Invalidation Prototype

NIP-41 is a proposal for a scheme whereby a Nostr identity key can be invalidated to a new one safely. nostr-protocol/nips#450

WARNING: This is a prototype implementation, use it only with test keys!

Previous version of this NIP/proto with custom crypto scheme: https://github.com/catenocrypt/nip41-proto0

Details

Terms:

• Key state: all predefined keys, plus the index of the currently valid keys
• Level: one element in the set of keys pre-generated iteratively
• Visible, denoted vis: the vis (public) part of a level, the key part, denoted e.g. A
• Hidden, denoted hid: the hid (secret) part of a level, the 'chain code' part, denoted e.g. A'

Operations:

• obtain current public key / secret key
• generate new set of keys
• generate next level key set from previous level keys
• invalidate: change current key and return keys needed for verification
• verify: verify validity of new key
• create invalidation Nostr event
• send invalidation event to relay
• listen for invalidation events, verify them

Details:

• As keys are for Nostr (using Schnorr sig), the type XOnlyPublicKey is used for pubkeys. This has the drawback that the parity is missing, and in verification both options have to be tried.

Building and Running

• Prerequisite: rust

• Try following commands:

cargo build

cargo run generate
cargo run
cargo run inv
cargo run

TODO

Contact

Nostr: optout@nostrplebs.com npub1kxgpwh80gp79j0chc925srk6rghw0akggduwau8fwdflslh9jvqqd3lecx

Sample Output

Some (truncated) sample output

generate

$ cargo run generate
NIP-41 "HD" Proto

WARNING: This is a prototype implementation, use it only with test keys!

State saved
$ 
$ cargo run
KeyState loaded (256 levels)
Level: 0  (out of 256)
Current pubkey:     	 npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  (6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd)
Previous pubkey:    	 None
Current secret key: 	 nsec1tr2sd..k9xq8n  (58d506857d..f55920)

invalidate

$ cargo run inv
KeyState loaded (256 levels)
Level: 0  (out of 256)
Current pubkey:     	 npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  (6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd)
Previous pubkey:    	 None
Current secret key: 	 nsec1tr2sd..k9xq8n  (58d506857d..f55920)
Invalidation info:
Invalidated:       	 npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  (6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd)
        new:       	 npub1y87rsvxluvak09zky47r20st8z9zecerm7marx7xwx7nr5zfrvqqu4ddls  (21fc3830dfe33b679456257c353e0b388a2ce323dfb7d19bc671bd31d0491b00)
     hidden:       	 3e5ea95edb1a94a3c75d822fffd8e3ffefac57a70e967bf3f01efd4222f288c0
Level: 1  (out of 256)
Current pubkey:     	 npub1y87rsvxluvak09zky47r20st8z9zecerm7marx7xwx7nr5zfrvqqu4ddls  (21fc3830dfe33b679456257c353e0b388a2ce323dfb7d19bc671bd31d0491b00)
Previous pubkey:    	 npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  (6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd)
Current secret key: 	 nsec1p47ht..sddtvy  (0d7d75bea7..6e1bdc)
verify?         	 true
Invalidation event: 
{"content":"key invalidation","created_at":1681419110,"id":"bb57b01956bfab8c3eed5e78039d0b57d545c72c59e7ecb0fcc8450544561992","kind":13,"pubkey":"21fc3830dfe33b679456257c353e0b388a2ce323dfb7d19bc671bd31d0491b00","sig":"d462c1e62b544bb53eab3a5a35f9aa371fcf3d10cb2102507c8141d999d27b65977647812f5deeeee405e16c699afa4e10987b5506452a3395bec2fdc90a886b","tags":[["p","6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd"],["hidden-key","3e5ea95edb1a94a3c75d822fffd8e3ffefac57a70e967bf3f01efd4222f288c0"]]}

State saved

Verify

$ cargo run verify npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a npub1y87rsvxluvak09zky47r20st8z9zecerm7marx7xwx7nr5zfrvqqu4ddls 3e5ea95edb1a94a3c75d822fffd8e3ffefac57a70e967bf3f01efd4222f288c0
NIP-41 "HD" Proto

WARNING: This is a prototype implementation, use it only with test keys!

Invalid vis     	 npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  (6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd)
New vis         	 npub1y87rsvxluvak09zky47r20st8z9zecerm7marx7xwx7nr5zfrvqqu4ddls  (21fc3830dfe33b679456257c353e0b388a2ce323dfb7d19bc671bd31d0491b00)
New hid         	 3e5ea95edb1a94a3c75d822fffd8e3ffefac57a70e967bf3f01efd4222f288c0
Verification result:  true

Listen

$ cargo run listen ws://umbrel.local:4848

Connected to relay ws://umbrel.local:4848
Subscribed to relay for invalidation events ...


Received event:  {"content":"key invalidation","created_at":1681419379,"id":"26f27fd9882c1b4120bc48e9eab0ab1a81416eb76bdbbe063f1b2c2e0e84c0ca","kind":13,"pubkey":"21fc3830dfe33b679456257c353e0b388a2ce323dfb7d19bc671bd31d0491b00","sig":"a414659c649071f4fb05e72e69850996d74eefbbd1adba48ef09841568f2e31429c40ab10f85bb02fd5e3907911ca9c238075f440c67631971ea46c5b4d9b1a3","tags":[["p","6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd"],["hidden-key","3e5ea95edb1a94a3c75d822fffd8e3ffefac57a70e967bf3f01efd4222f288c0"]]}
'P-tag' (invalidated):               npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  (6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd)
Pubkey (new):                        npub1y87rsvxluvak09zky47r20st8z9zecerm7marx7xwx7nr5zfrvqqu4ddls  (21fc3830dfe33b679456257c353e0b388a2ce323dfb7d19bc671bd31d0491b00)
'Hidden-key-tag' (invalidated hid):  3e5ea95edb1a94a3c75d822fffd8e3ffefac57a70e967bf3f01efd4222f288c0

Invalidate  npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  in favor of  npub1y87rsvxluvak09zky47r20st8z9zecerm7marx7xwx7nr5zfrvqqu4ddls !

Verification result: true 


Received event:  {"content":"key invalidation","created_at":1681419385,"id":"d7bd5a85094ea2c75629a795aca7abf617ee5675cb033f158181fff316c5a9ab","kind":13,"pubkey":"21fc3830dfe33b679456257c353e0b388a2ce323dfb7d19bc671bd31d0491b00","sig":"2f21af29d37456390bfcfd0c2eda66e3eefa29d37085f52d5aabeb603d7621c5ffa985cdfd193a8cc56515d29847a95128122313d8b67b87b58f5cc0ebf95dcb","tags":[["p","6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd"],["hidden-key","3e5ea95edb1a94a3c75d822fffd8e3ffefac57a70e967bf3f01efd4222f288c0"]]}
'P-tag' (invalidated):               npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  (6a123fef0f52b6bd6a188b93f0322f3c828a8815cf83a106816bc343d2e4e5dd)
Pubkey (new):                        npub1y87rsvxluvak09zky47r20st8z9zecerm7marx7xwx7nr5zfrvqqu4ddls  (21fc3830dfe33b679456257c353e0b388a2ce323dfb7d19bc671bd31d0491b00)
'Hidden-key-tag' (invalidated hid):  3e5ea95edb1a94a3c75d822fffd8e3ffefac57a70e967bf3f01efd4222f288c0

Invalidate  npub1dgfrlmc022mt66sc3wflqv308jpg4zq4e7p6zp5pd0p585hyuhwsp75h9a  in favor of  npub1y87rsvxluvak09zky47r20st8z9zecerm7marx7xwx7nr5zfrvqqu4ddls !

Verification result: true