After more than 2 years in existence, there is still no reliable nip46 signer. There is a tension between self-custody and reliability of the signer: you either keep the keys on your device (which is unreliable, especially on mobile), or you upload the keys to a signer server (which usually means you are 100% trusting the server to not steal your keys). To learn more about the issue, read here.

AWS Nitro enclaves promise to solve the problem of lack of trust for a particular service. The code running inside an enclave is fully isolated by AWS from the person launching it. The attestation signed by AWS and reproducible open-source code let anyone verify what exactly is happening inside the enclave (as long as one trusts AWS VM infrastructure). For a signer server in particular, this means there's much less chance for your keys to be stolen or hacked. Add to the mix a tie to npubs of people who built and launched the service, and you can use Nostr and WoT to discover and interact with provably safe services running inside AWS enclaves. The noauth-enclaved is the first prototype of such service.