> There is NIP

For reference NIP-26
Proposed and used by minds.com

> Hardware wallet that signs events  and delegations

Standard HW, as we know them today, are ok only to sign a delegation, because it is hard to use them with the high interactions frequency typical of Nostr.
Someone is doing some tests with the SeedSigner.

dtonon

There is NIP that specifies key delegation: publishing a note that gives a certain client app permission to sign notes for you. That permission can then be revoked at any time in case the app is compromised.

Regarding the storage and usage of the private key:

Hardware wallet that signs events  and delegations > Native containes apps where private key is hot > browser extension that contains private key and signs events > pasting private key on webapp

nostr

What is the best way to secure a Nostr private Key?

There is NIP that specifies key delegation: publishing a note that gives a certain client app permission to sign notes for you. That permission can then be revoked at any time in case the app is compromised.

Regarding the storage and usage of the private key:

Hardware wallet that signs events  and delegations > Native containes apps where private key is hot > browser extension that contains private key and signs events > pasting private key on webapp