A chirp spread spectrum (CSS) receiver may reject, based on multiple data alignment chirps that includes an attribute identifier that is a mismatch to one or more preconfigured identifiers, a message early and before fully receiving/decoding the message. The multiple data alignment chirps may enable usage of a larger range of IDs than a single chirp signal. A receiver may receive a sequence of training chirps for symbol alignment followed by multiple opposite chirps for data alignment. Training chirps may be processed through a fast-Fourier transform (FFT) and the resulting values accumulated until a threshold is exceeded. Using symbol alignment from the training chirps, the receiver may decode multiple opposite chirps that indicate data alignment and comprise an encoded identifier. The receiver may reject the message and terminate further message processing based on the encoded identifier being a mismatch to preconfigured identifiers or attributes indicated by the encoded identifier.