Toeplitz Sliding Window
The hash a NIC uses to pick a receive queue. No lookup tables, no multiplication - just shifts and XOR.
The demo is fully interactive: step, rewind, play through, or change the input. Arrow keys move a bit at a time; space plays and pauses.
What this demo shows
The hero is a 320-bit key tape with a 32-bit window framed on it, sliding one notch per input bit. It makes the hard part visible at a glance - row i of the Toeplitz matrix is simply the key read from bit i - which is exactly why the whole matrix collapses into a single register.
Input bytes are laid out bit by bit. A 1 fires result ^= window and lights up red; a 0 only slides the window. Window and result share one 32-column grid, so the XOR reads vertically and flipped bits are outlined.
The last panel compares both directions of a connection. With the standard key, forward and reverse land in different queues - one TCP connection split across two cores. Switch to a symmetric key and both directions hash alike. For NAT, stateful firewalls and traffic analysis, this is the whole problem in one screen.
Every intermediate state is computed live, not a recorded animation. The implementation checks out against the Microsoft RSS reference vectors.