tscp (tiny secure communication protocol)

An E2EE (endpoint-to-endpoint encryption) is possible to implement on resource constraint microcontrollers using a high-level programming language. A secure protocol based on a well-known key-exchange technique Diffie-Hellman-Merkle and TLS1.3 style session-key negotiation is implemented and tested.

Large primes are not needed in the modified DHM key-exchange protocol pow(x,b)%P == pow(y,a)%P. MicroPython modules are developed to provide identification, authentication, and privacy of messages between two communicating end-points. The limiting factor of large integers arithmetic in Python is the amount of runtime time RAM available. An end-to-end is an application-level protocol and thus can be used for any form of message exchange.

This work entitled Simple E2EE Secure Communication Protocol for Tiny IoT Devices was submitted to The 19th. International Conference on Cooperative Design, Visualization and Engineering - CDVE2022. The proceedings book will be published by the Lecture Notes in Computer Science (LNCS).

Testing (with debugging)

MicroPython v1.19.1-358-g0b26efe73-kaki5 on 2022-09-02; ESP32 BLE (KAKI5) module with ESP32
>>> import test_tscp_aes_debug
0 ----------------------------------
This is the start of a beautiful day!
b'Hello:KAKI5-1-0-A:C-1-2-38:oXo|AES:102:116297090366876477071146'
b'Hey:AES:5b750788b9c20329015a0d0f41a060db05f708badfc048792c17770c01d6e142:27756140084870699242461'
b'5b750788b9c20329015a0d0f41a060dbfd8a61f66078db94502d0e51873a3468cf92f1012da188887d5780d1b0b372f9c7c49c34dc0a17f86ef052afafb0cf94:e12354abaf648620c8bf7bb96a023c0d0437be0e7b5336ba003106d1c360fe5f'
Bob:
   Client node authenticates? True C-1-2-38
   Server node authenticates? True S-9-12-10
   Data hash ok? True
SRV msg: b'188dc78a7f2707be008a3d33ce39417be0d4e71a6868d80e849768b8abe05da5aaa472a2ba34eb789431fa6ccf6fa3baff921a7c5b45b8cafbdea75c2fae2dfc:50b8f3efe52dfc7c0c139f64f24d1b31d8fdbde293d5ebd6175dbc98a9b4e06b'
Raw Data:188dc78a7f2707be008a3d33ce39417be0d4e71a6868d80e849768b8abe05da5aaa472a2ba34eb789431fa6ccf6fa3baff921a7c5b45b8cafbdea75c2fae2dfc
Hash: 50b8f3efe52dfc7c0c139f64f24d1b31d8fdbde293d5ebd6175dbc98a9b4e06b
SRV data: S-9-12-10:C-1-2-38:THIS IS THE START OF A BEAUTIFUL DAY!
It hash: b'50b8f3efe52dfc7c0c139f64f24d1b31d8fdbde293d5ebd6175dbc98a9b4e06b'
Alice:
   Client node authenticates? True C-1-2-38
   Server node authenticates? True S-9-12-10
   Data hash ok? True
THIS IS THE START OF A BEAUTIFUL DAY!
1 ----------------------------------
This is the start of a beautiful day!
b'Hello:KAKI5-1-0-A:C-9-6-11:oXo|AES:101:37324430542233743414781'
b'Hey:AES:d51b9827885fbdc7e9deea374a76428649c3af9d9a81b6f590fe01da64659bc7:64010375101150211120541'
b'd51b9827885fbdc7e9deea374a76428617bfaf94c4ddb5731422cb538006eb678133432938431da02756d476c9889bc1dc1125b3485626d5e0b9aa313b44c314:c589638603ed8a484d642f622fb0c5eea2c4febee2d2ed75e5a6dacda6b23d66'
Bob:
   Client node authenticates? True C-9-6-11
   Server node authenticates? True S-13-6-28
   Data hash ok? True
SRV msg: b'd173839522a4bb7236f8baf9ed85bbd2600600d5dcff141c80f32da8c0e8d4a04f6b01cc5cd2cc5b90d221cbb1a05712fa93c2c7195d8b70900228e170e48635:adbf841852fb500e03c5460e1b0865d97d830105869d60c94d7527e9958ab506'
Raw Data:d173839522a4bb7236f8baf9ed85bbd2600600d5dcff141c80f32da8c0e8d4a04f6b01cc5cd2cc5b90d221cbb1a05712fa93c2c7195d8b70900228e170e48635
Hash: adbf841852fb500e03c5460e1b0865d97d830105869d60c94d7527e9958ab506
SRV data: S-13-6-28:C-9-6-11:THIS IS THE START OF A BEAUTIFUL DAY!
It hash: b'adbf841852fb500e03c5460e1b0865d97d830105869d60c94d7527e9958ab506'
Alice:
   Client node authenticates? True C-9-6-11
   Server node authenticates? True S-13-6-28
   Data hash ok? True
THIS IS THE START OF A BEAUTIFUL DAY!
# error: 0 in 2 tests
>>> 

The tscp.py script was produced by pyminify. Please read tscp_debug.py and test_tscp_aes_debug.py for more information on how this module works.