# tea3-py

More documentation available [here](https://hadow.fr/articles/tea3.pdf) 

## install

```bash
python -m venv .venv
source .venv/bin/activate
pip install -e .
```

## run tests

```bash
pip install pytest
pytest
```

## run linear and differential bias empirical tests

in the venv

```bash
tea3-linear-bias
tea3-differential-bias
```

## derive lookup tables

```bash
lookup-tables
```

## run sagemath script

`deactivate` the venv first, then with sagemath installed:

```bash
./run_sage.sh
```

Modes are:  
| Mode                                           | Explanation |
| ---------------------------------------------- | ----------- |
| 1. Classic inspection                          | run n steps                                                              |
| 2. Advanced inspection with forced 0 or 1 bits | run n steps but with bits forced to 0 or 1                               |
| 3. Exhaustive variable-change search           | -                                                                        |
| 4. S box analysis                              | -                                                                        |
| 5. Variable XOR                                | XOR chosen bits inside a register and check the evolution during n steps |
| 6. F31, F32 analysis                           | -                                                                        |
| 7. Exhaustive XOR search                       | XOR bits inside a register, returns the best combination (least number of monomials)|
| 8. Cube attack search (symbolic)               | offline part of the cube attack (a precomputed model can be used)        |
| 9. Cube attack search (oracle)                 | offline part of the cube attack (uses TEA-3 cipher as an oracle)         |
| 10. Precompute and save model                  | precompute n steps and save the model                                    |
| 11. Load model                                 | load a saved model                                                       |



n steps can be precomputed and then loaded for the offline part of the cube attack with the menu entries 10 and 11.