You can use bot settings to encrypt your bot file or renew your bot file secret.
With an open bot configuration (.bot file), you can click on the gear icon to bring up bot settings.
CAUTION Should you choose to encrypt your bot file, please keep the key in a secure place (e.g. Azure Key Vault(https://azure.microsoft.com/en-us/services/key-vault/)). Emulator does not provide any key recovery mechanisms at this point.