Concept render of the intended physical Bittosser hardware.
One seed, two devices. The Classic and Mini views share the same seed. Use the switch at the top to change view at any time — words, position and edit mode carry across.
Switch on. The left knob selects 12W or 24W. Moving it wipes the device and starts a fresh seed. OFF blanks the display.
Toss coins. Tap the felt, or press Toss, to throw 11 coins. A coin showing its letter is a one; a blank coin is a zero. Hold the felt to copy the toss into the current word.
Enter bits by hand. Press Edit to work on the current word. The cursor starts at A; turn the right knob, or use left/right, to move it, and Enter flips the bit underneath. Press Edit again to finish the word.
Read the seed. Outside edit mode the knob, or up/down, steps through the words. A word you have not touched yet shows its number and nothing else.
The knob. Drag it in a line or circle it like a real knob. On a touchscreen a tap is Enter. With a mouse, click it to hand it the scroll wheel — a blue ring shows it is attached; click again, or press Escape, to let go.
Checksum. When every word is filled the BIP-39 checksum is written into the tail of the last word — four bits on 12W, eight on 24W, marked by the amber rule. The amber CHECKSUM badge flashes whenever it is recalculated.
Keyboard. Space is Edit, Enter is Enter, arrows move.
Switch to 12 or 24 to power on. The coins are M&M-shaped (lens/domed) — the curved shape makes them tumble and flip freely when shaken in a cup for a fair toss, and keeps them from stacking or covering one another when they land. Each coin has one blank face (=0) and one lettered face A–K (=1). Toss (tap the felt or space), then press the keys for the coins that show a letter — order doesn't matter. The display shows the letters you've pressed so you can compare it against the marked coins; each pressed bit lights its LED red. Press ENTER to finalize: the BIP-39 word appears briefly, the 0-bits light green, and the device moves on to the next word. Holding the felt copies the coins into the current word the same way. Browse words with ▲/▼ (or tap/hold ↑/↓ buttons); press ENTER, a letter or ⌫ to start editing a word, and ENTER again to commit it. ⌫ undoes your last press (hold clw to clear the entire word). Hold B for binary display, hold D for decimal display. Hold C (clr) to clear all words. VALID SEED lights once every word is committed and the checksum is good. Yellow LEDs mark checksum positions in the final word — these bits are calculated, not retained as entropy. (To enter an all-blank word, press ENTER twice.)
Questions? Email [email protected]
Bit Tosser · v
Concept render of the intended physical Bittosser hardware.
This is an interactive demo. Any seed it helps you generate here — including the simulated coin tosses — must be treated as insecure. Do not use a seed phrase produced in this demo to hold real funds.
The real Bit Tosser hardware has no random generator at all — the entropy comes only from your own physical coin tosses, so it does not share this weakness.