483 IEEE DOORSH
483 : IEEE DOORSH
- Author: Koło Naukowe BAZA, Politechnika Warszawska — ZT, PN, MK, JT, KK
- Description: PIN-authorized SIMON64/128 challenge-response authenticator with a 4x4 keypad and passive buzzer
- GitHub repository
- Open in 3D viewer
- Open in Tiny Tapeout Explorer
- Clock: 1000000 Hz
How it works
IEEE DOORSH is a PIN-authorized SIMON64/128 challenge-response authenticator developed by Koło Naukowe BAZA, Politechnika Warszawska (ZT, PN, MK, JT, KK) for Tiny Tapeout IHP26b.
The ASIC scans a 4×4 matrix keypad. Entering 1234 authorizes exactly one
64-bit challenge. The host sends the challenge over the SHIFT64 serial link,
the ASIC encrypts it with the fixed demonstration key, and the host reads the
64-bit response in a second frame. A wrong PIN does not open the interface or
produce a response. Three wrong PINs block further attempts until cold reset.
SCLK is sampled by the 1 MHz project clock; it is not an independent clock.
Keep each SCLK high and low phase at least 16 project-clock cycles and change
CS_n only while SCLK is low.
How to test
- Apply reset and enable the project.
- Press and release
1,2,3,4. - Wait for
CHALLENGE_READYonuo_out[0]. - Send
F15654A8D25FFA1C, MSB first, onSDIusing one 64-bit frame. - Wait 10,000 project-clock cycles (10 ms at 1 MHz).
- Read a second 64-bit frame from
SDO.
The expected response is BA2A5234DEADBEEF for the fixed key
BA2A1918131211100B0A090803020100. The distinctive hexadecimal pattern makes
a successful transaction easy to recognize without any text decoding.
External hardware
- passive 4×4 matrix keypad;
- pull-ups on the four keypad column inputs;
- host capable of the SHIFT64 timing described above;
- passive buzzer with a suitable transistor or logic driver.
uo_out[3] generates a nominal 2 kHz tone for the passive buzzer for 50 ms
after an accepted key event. Do not power a high-current transducer directly
from the Tiny Tapeout output pad.
Pinout
| Pins | Function |
|---|---|
ui_in[3:0] |
Keypad columns C0–C3, active low |
ui_in[4] |
SHIFT64 SDI |
ui_in[5] |
SHIFT64 SCLK |
ui_in[6] |
SHIFT64 CS_n |
ui_in[7] |
Unused |
uo_out[0] |
CHALLENGE_READY |
uo_out[1] |
Unused, tied low |
uo_out[2] |
SHIFT64 SDO |
uo_out[3] |
2 kHz passive-buzzer drive |
uo_out[7:4] |
Unused, tied low |
uio[3:0] |
Open-drain keypad row enables R0–R3 |
uio[7:4] |
Unused, high impedance |
The key and PIN are public demonstration constants. IEEE DOORSH is an educational ASIC demonstrator, not a production security device.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | keypad column 0, active low | CHALLENGE_READY after correct PIN | keypad row 0 open-drain enable |
| 1 | keypad column 1, active low | unused, tied low | keypad row 1 open-drain enable |
| 2 | keypad column 2, active low | SHIFT64 SDO | keypad row 2 open-drain enable |
| 3 | keypad column 3, active low | 2 kHz passive buzzer drive | keypad row 3 open-drain enable |
| 4 | SHIFT64 SDI | unused, tied low | unused |
| 5 | SHIFT64 SCLK | unused, tied low | unused |
| 6 | SHIFT64 CS_n | unused, tied low | unused |
| 7 | unused | unused, tied low | unused |