Error: the author of this message is unknown to Keybase.

I believe the cause of this is if a user creates a keybase keypair and then chooses to replace that keypair with one of their own 4096 keypairs.

Whenever attempting to decrypt a message sent to user who's updated their key this error occurs, or when user attempts to send a message to someone else they get this error when the message is attempted to be decrypted on their end.

If using another PGP program to decrypt with the appropriate keys the decryption will still work appropriately even when the message has been encrypted through keybase.io, so the actual PGP message is being encrypted properly.

No files, tests, or entry points are named. Start by reproducing the error after replacing a Keybase keypair with a 4096-bit key, then trace message decryption and author lookup. Done means messages decrypt successfully and identify the author after the key is replaced.

Written by the indexing model from the issue text.