The SYSV checksum algorithm is commonly used, legacy checksum algorithms. It has been implemented in UNIX System V and is also available through the GNU sum command line utility.
- Digest sizes - 16 bits
- Structure - CRC
- Re-arranging the same bytes in another order does not change the checksum.
- Increasing one byte and decreasing another byte by the same amount does not change the checksum.
- Adding or removing zero bytes does not change the checksum.
The main part of this algorithm is simply adding up all bytes in a 32-bit sum.