Hash Code and Checksum - what's the difference?

Question

My understanding is that a hash code and checksum are similar things - a numeric value, computed for a block of data, that is relatively unique.

i.e. The pr

Answer 1

There is a different purpose behind each of them:

• Hash code - designed to be random across its domain (to minimize collisions in hash tables and such). Cryptographic hash codes are also designed to be computationally infeasible to reverse.
• Check sum - designed to detect the most common errors in the data and often to be fast to compute (for effective checksumming fast streams of data).

In practice, the same functions are often good for both purposes. In particular, a cryptographically strong hash code is a good checksum (it is almost impossible that a random error will break a strong hash function), if you can afford the computational cost.