Checksum

A sum of the digits in a given transmission modulo some number. The simplest form of checksum is a parity bitappended on to 7-bit numbers (e.g., ASCII characters) such that the total number of 1s is always Even (``evenparity'') or Odd (``odd parity''). A significantly more sophisticated checksum is the Cyclic RedundancyCheck (or CRC), which is based on the algebra of polynomials over the integers (mod 2). It is substantiallymore reliable in detecting transmission errors, and is one common error-checking protocol used in modems.

References

Press, W. H.; Flannery, B. P.; Teukolsky, S. A.; and Vetterling, W. T. ``Cyclic Redundancy and Other Checksums.'' Ch. 20.3 in Numerical Recipes in FORTRAN: The Art of Scientific Computing, 2nd ed. Cambridge, England: Cambridge University Press, pp. 888-895, 1992.

• Positive
• Positive Definite Function
• Positive Definite Matrix
• Positive Definite Quadratic Form
• Positive Definite Tensor
• Positive Integer
• Positive Semidefinite Matrix
• Positive Semidefinite Quadratic Form
• Postage Stamp Problem
• Posterior Distribution
• Postnikov System
• Postulate
• Potato Paradox
• Potential Function
• Potential Theory
• Pothenot Problem
• Poulet Number
• Power
• Power Center
• Power (Circle)
• Power Curve
• Powerfree
• Powerful Number
• Power Line
• Power Point