A modern Simple-DES workbench for visual learners
Pair the interactive form with the live visualizer to see how every permutation and round function manipulates your bits. Toggle between encrypt and decrypt without losing context.
Feistel clarity
Track each swap, permutation, and XOR in plain language as you step through the rounds.
Binary-first inputs
Mono-spaced fields keep bits aligned so you can spot mistakes before processing.
Safe experimentation
Encrypted Base64 output drops straight into decrypt mode so you can reverse immediately.
Shareable state
Copy the final block with a single tap to document the lesson or hand off to a teammate.
Pro tip
Encrypt a short phrase, copy the Base64 output, and drop it right back into decrypt mode to watch the reverse sequence unfold.
Key Size
10 bits
Block Size
8 bits
Rounds
2 Feistel passes
Walk the sequence
Everything the visualizer will highlight
Each milestone mirrors a group of steps you will see animate in the workspace below. Hover over each state in the visualizer to inspect the intermediate bit strings.
Key scheduling
Permutation P10 and left rotations sculpt two subkeys (K1 and K2) from your binary key.
Initial permutation
Plaintext bits are reordered via IP to prime the Feistel structure for diffusion.
Round functions
Expansion, key mixing, S-box lookups, and P4 compression drive each Feistel round.
Inverse permutation
After the second swap, IP⁻¹ restores the bit order to reveal the final block.
Hands-on Simple-DES workspace
Run the algorithm at your own pace. Configure plaintext, ciphertext, and keys, then watch the visualizer mirror every round before copying the final block.
Enter text and click to see the algorithm in action