Reference implementation
========================

This folder contains the reference implementation for Lilliput-AE.

It is organized as follows:

`src`
-----

Contains parameter-independent code for the reference implementation:

- `lilliput-ae.h`: main API
- `lilliput-ae-i.c`: implementation of Lilliput-Ⅰ (ΘCB3-based)
- `lilliput-ae-i.c`: implementation of Lilliput-Ⅱ (SCT-2-based)
- `ae-common.h`: internal helper functions used by both AE schemes
- `tweakey.*`: implementation of Lilliput-TBC's tweakey schedule
- `cipher.*`: implementation of the tweakable block-cipher
  Lilliput-TBC
- `constants.*`: tabulated data for
    - the tweakey schedule's permutation h
    - the tweakey schedule's multiplication sequences P~1~ to P~6~
    - Lilliput-TBC's S-box
- `parameters.h`: byte sizes for inputs and outputs (depends on
  parameter-dependent `_parameters.h` files)

There is one subfolder for each variant of the Lilliput-AE family,
named `${mode}-${keybits}`:

- mode is either i (for ΘCB3) or ii (for SCT-2)
- keybits is either 128, 192 or 256

`test`
-------------

Contains test vectors. There is one subfolder per member of the
Lilliput-AE family, as well as:

- `common.mk`: makefile recipes for test programs
- `debug.h`: helper functions to dump intermediate values, used in
  the trace-generating patches
- `test-helpers.h`: helper functions for test code

`nist`
------

Contains code to

- generate the directory structure required by NIST
- compile each member of the Lilliput-AE family against NIST's
  `genkat_aead.c`
- generate test vectors
- package code and test vectors together into `results/crypto_aead`

The code can be run with `make nist`.

`traces`
--------

Contains patches to add print statements for inputs, outputs and
intermediate values. `make traces` will

- apply the patches
- run the trace programs
- collect traces
- revert the patches