Policy Setting: AWS > SNS > Topic > Encryption at Rest > Customer Managed Key

resource "turbot_policy_setting" "aws_sns_topic_encryption_at_rest_customer_managed_key" {
  resource = turbot_policy_pack.main.id
  type     = "tmod:@turbot/aws-sns#/policy/types/topicEncryptionAtRestCustomerManagedKey"
  # Add your CMK id/arn/alias below
  value = "alias/turbot/default"
}