class ActiveStorage::Blob

def find_signed!(id, record: nil, purpose: :blob_id)

It will also raise an +ActiveRecord::RecordNotFound+ exception if the valid signed id can't find a record.
exception if the +signed_id+ has either expired, has a purpose mismatch, or has been tampered with.
Works like +find_signed+, but will raise an +ActiveSupport::MessageVerifier::InvalidSignature+ 
def find_signed!(id, record: nil, purpose: :blob_id)
  super(id, purpose: purpose)
end