We provide throughput rates, measured in machine cycles-per-byte, for the processing of messages of various byte-lengths by UMAC and its underlying hash function UHASH. We use cycles-per-byte because it makes possible efficiency comparisons between processors running at different speeds. To convert to bytes-per-second, divide your processor's cycles-per-second (Hz) by the reported cycles-per-byte to get bytes-per-second. For example, a 1 GHz processor spending 2.0 cycles-per-byte processes 1e9 / 2.0 = 0.5e9 bytes-per-second (500 MB/sec).

We report on throughput speeds for several message lengths; 44, 552 and 1500 bytes being very common packet sizes found on the Internet.

There are three tag lengths defined for UMAC; 32, 64 andd 96 bits. We advocate the use of 64-bit authentication tags for most purposes. UMAC and UHASH, however, provide flexibity in meeting performance and security needs. Longer or shorter outputs can be produced with proportionally longer or shorter computation time and proportionally stronger or weaker security. For a detailed discussion of security considerations, see the UMAC specification.