# LASS/Airbox and IOTA Integration ###### tags: `iota` :::info Collaboration between [LASS](http://lass-net.org/) community and [Distributed Ledger Labortory](http://dlt.csie.ncku.edu.tw/), National Cheng Kung University, Taiwan Please contact `<jserv@ccns.ncku.edu.tw>` for further information. ::: Overview: [LASS_and_IOTA_Integration.pdf](https://drive.google.com/open?id=1fYexv7dpHh9LJ0rTK_vjlse8EOtUSlhN) Tutorial: [IOTA/TangleID + 空氣盒子教學](https://hackmd.io/s/H1HxM-2hz) ## What is IOTA? * next generation public distributed ledger * Tangle * based on a Directed Acyclic Graph * no Blocks * no Chain * no Miners * ![](http://i.imgur.com/1vcRSLx.png) * The Tangle Serguei Popov∗ October 1, 2017. Version 1.3 * features * Scalability * No Transaction Fees * Decentralization * Quantum-immunity * [What is IOTA](https://iota.readme.io/docs/what-is-iota) ## What is LASS? * "LASS" stands for "Location Aware Sensor System" * open source and charity * totally 5346 device in Taiwan (2018/2/10) * [PM2.5 OPEN DATA PORTAL](https://pm25.lass-net.org/zh_tw/) * [LASS - Data specification](https://paper.dropbox.com/doc/LASS-Data-specification-86K8vkbGWyCG7aMiP1odg) * [LASS - data format](https://paper.dropbox.com/doc/LASS-data-format-Sk7rv3Omok5Sr4nkVO1Cd) * Hack4U device * [tutorial](https://paper.dropbox.com/doc/HACK4U4-Hack4u-87Live-TRmqFxXLJHXrKBo4kiR6O) * ![Hack4U device](https://pm25.lass-net.org/LASS/assets/img/devices/HACK4U-87live-Zero.png) ## Why do we need IOTA for LASS? * reduce latency and operating costs * reduce the risk of attack and destruction * ensure data integrity and proof-of-existence (PoE) * reward platform, feedbacks with IOTA token * ![](https://i.imgur.com/D5O0hyu.png) ## Technical Details ### Scenario ![](https://i.imgur.com/AyF4iNQ.png) ### Firmware Update * USB * OTA (regional network) * [Ameba Arduino OTA](https://www.amebaiot.com/ameba-arduino-ota/) * OTA (server) *(WIP)* ### Data Encoding - [ ] Data - header | Field | Description | Values | | ------------- |:--------------------------:| ------:| | ver_format | MQTT record format version | 3 (default) | | FAKE_GPS | GPS presence | 0 (GPS available), 1 (no GPS) | | app | app name | | | ver_app | LASS version | | | device_id | unique | | | gps_lon | longitude | | | gps_lat | latitude | | - body - date / time - string : 2017-12-17 07:01:55 - epoch : 1513494115 (32 bits) - s_d0 - PM2.5 - 0 ~ 500 (16 bits) - s_d1 - PM10 - 0 ~ 500 (16 bits) - s_t0 - temperature - -100 ~ 60 (8 bit) - s_h0 - humidity - 0 ~ 100 (8 bit) - [ ] Huffman coding * more common symbol <=> fewer bits * difference between current and previous value * e.g. temperature : 20, 21, 21, 19 => 20, +1, +0, -2 * analysis of historical data * frequency for each symbol ('-50' ~ '49') * ![](https://i.imgur.com/Fumigcm.png) * there are **0.0108%** data out of -50 ~ 49 * discard these unreasonable data * discard ratio : **0.0432%** * Huffman’s algorithm pseudocode ``` http://cseweb.ucsd.edu/~kube/cls/100/Lectures/lec8/lec8-15.html 0. Determine the count of each symbol in the input message. 1. Create a forest of single-node trees. Each node in the initial forest represents a symbol from the set of possible symbols, and contains the count of that symbol in the message to be coded. Symbols with a count of zero are ignored (consider them to be impossible). 2. Loop while there is more than 1 tree in the forest: 2a. Remove the two trees from the forest that have the lowest count contained in their roots. 2b. Create a new node that will be the root of a new tree. This new tree will have those two trees just removed in step 2a as left and right subtrees. The count in the root of this new tree will be the sum of the counts in the roots of its subtrees. Label the edge from this new root to its left subtree “1”, and label the edge to its right subtree “0”. 2c. Insert this new tree in the forest, and go to 2. 3. Return the one tree in the forest as the Huffman code tree. ``` * result | | compressed / uncompressed size | uncompressed / compressed size | | -- | -- | -- | | Theoretical value | 12.94 % | 7.73 | | Experimental value | 9.984 % | 10.02 | * Experimental ![](https://i.imgur.com/xbPPS3e.png) ``` -50 1110101010110111001 -49 1110101010110001111 -48 1110101010110101101 -47 1110101010110111000 -46 1110101010110110000 -45 1110101010110001100 -44 1110101010110011000 -43 1110101010110111101 -42 1110101010110100101 -41 1110101010110100010 -40 1110101010110010000 -39 1110101010110010111 -38 1110101010110011001 -37 1110101010110101100 -36 1110101010110010110 -35 1110101010110111111 -34 1110101010110111100 -33 1110101010110011111 -32 1110101010110101111 -31 1110101010110110100 -30 1110101010110110101 -29 1110101010110110111 -28 1110101010110010011 -27 1110101010110101011 -26 1110101010110001001 -25 1110101010110100001 -24 1110101010110100000 -23 1110101010110100110 -22 1110101010110000011 -21 1110101010110000010 -20 1110101010110010100 -19 111010101011111110 -18 1110101010110000000 -17 1110101010111000000 -16 111010101011111101 -15 111010101011111100 -14 111010101011111010 -13 111010101011100111 -12 111010101011100110 -11 111010101011100100 -10 111010101011100010 -9 111010101011101 -8 1110101010101 -7 1110101011 -6 111010100 -5 1110100 -4 1111 -3 0101 -2 110 -1 001 0 10 1 000 2 011 3 0100 4 11100 5 111011 6 11101011 7 11101010100 8 1110101010100 9 111010101011110 10 111010101011100001 11 111010101011100011 12 111010101011100101 13 111010101011111000 14 111010101011111001 15 111010101011111011 16 1110101010110110010 17 1110101010110110011 18 1110101010111000001 19 1110101010110000001 20 111010101011111111 21 1110101010110010101 22 1110101010110011010 23 1110101010110011011 24 1110101010110100111 25 1110101010110001000 26 1110101010110101010 27 1110101010110010010 28 1110101010110101110 29 1110101010110001010 30 1110101010110110001 31 1110101010110011100 32 1110101010110100100 33 1110101010110010001 34 1110101010110000111 35 1110101010110011110 36 1110101010110111110 37 1110101010110100011 38 1110101010110110110 39 1110101010110000110 40 1110101010110101001 41 1110101010110000101 42 1110101010110001101 43 1110101010110011101 44 1110101010110101000 45 1110101010110111011 46 1110101010110001011 47 1110101010110111010 48 1110101010110000100 49 1110101010110001110 ``` - [ ] Base64 * represent binary data in an ASCII string * 6 bits <=> 1 char * `ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/` - [ ] Compression Ratio * datatype : **ASCII string** * data : **body** (epoch, pm10, pm2.5, temperature, humidity) * bundle **n-minutes** sensor data (default n = 10) * uncompressed / compressed : 27n / (10.93 + 2.4n) , **7.73** (n = 10) ## [TangleID](https://tangleid.github.io/) API * command: `new_claim` * uuid: derive from MAC address * msg: ver_format|FAKE_GPS|app|ver_app|device_id|gps_lon|gps_lat|latitude|encoded string ``` Make a HTTP request POST /tangleid_backend/api/ HTTP/1.1 Host: 140.116.82.61 Content-Type: application/json Content-Length: 185 {"command":"new_claim","uuid": "LASSBBMBOBABKBCBWAAB","part_a":"LASSBBMBOBABKBCBWAAB","part_b":"LASSBBMBOBABKBCBWAAB","exp_date":"","claim_pic":"","msg":"3|1|PM25|live|8CE7A927|120.971042|24.801909|Wn6jsKnVQAFuqqgALdVVCtVVSRVVU"} ``` * [TangleID API Reference](https://hackmd.io/s/SySrMTHJz) ## Data verification *(WIP)* ``` $ cat Makefile all: g++ main.cpp encode.h -o main test_one: @./main @python3 decode.py diff test_input.txt test_output.txt test: for i in `seq 1 1 1000`; \ do \ make test_one ; \ done ``` ``` $ make test for i in `seq 1 1 1000`; \ do \ make test_one ; \ done make[1]: Entering directory '/home/bevis/IOTA_LASS' diff test_input.txt test_output.txt make[1]: Leaving directory '/home/bevis/IOTA_LASS' make[1]: Entering directory '/home/bevis/IOTA_LASS' diff test_input.txt test_output.txt make[1]: Leaving directory '/home/bevis/IOTA_LASS' make[1]: Entering directory '/home/bevis/IOTA_LASS' diff test_input.txt test_output.txt ... ``` ## Open Data API *(WIP)* - python ``` $ python3 IOTAxLASS.py BBMBOBABKBCBWAAB { "device_id": "8CE7A927", "s_t0": "24", "app": "PM25", "FAKE_GPS": "1", "s_d0": "32", "s_d1": "36", "ver_format": "3", "s_h0": "67", "gps_lon": "120.971042", "ver_app": "live", "timestamp": "2018-02-02 16:31:11", "gps_lat": "24.801909" } { "device_id": "8CE7A927", "s_t0": "24", "app": "PM25", "FAKE_GPS": "1", "s_d0": "31", "s_d1": "32", "ver_format": "3", "s_h0": "66", "gps_lon": "120.971042", "ver_app": "live", "timestamp": "2018-02-02 16:32:11", "gps_lat": "24.801909" } { "device_id": "8CE7A927", "s_t0": "24", "app": "PM25", "FAKE_GPS": "1", "s_d0": "32", "s_d1": "35", "ver_format": "3", "s_h0": "66", "gps_lon": "120.971042", "ver_app": "live", "timestamp": "2018-02-02 16:33:11", "gps_lat": "24.801909" } { "device_id": "8CE7A927", "s_t0": "24", "app": "PM25", "FAKE_GPS": "1", "s_d0": "31", "s_d1": "34", "ver_format": "3", "s_h0": "67", "gps_lon": "120.971042", "ver_app": "live", "timestamp": "2018-02-02 16:34:11", "gps_lat": "24.801909" } { "device_id": "8CE7A927", "s_t0": "24", "app": "PM25", "FAKE_GPS": "1", "s_d0": "32", "s_d1": "35", "ver_format": "3", "s_h0": "67", "gps_lon": "120.971042", "ver_app": "live", "timestamp": "2018-02-02 16:35:12", "gps_lat": "24.801909" } ... ``` - php ![](https://i.imgur.com/nXdU05y.png) ![](https://i.imgur.com/i3d1vax.png) ## IOTA Message Length - 2187 trytes - Signature message fragment. In case there is a spent input, the signature of the private key is stored here. If no signature is required, it is empty (all 9's) and can be used for storing the message value when making a transfer. More to that later. - [The Anatomy of a Transaction ](https://iota.readme.io/docs/the-anatomy-of-a-transaction) - original : < 700 trytes - compressed (avg): 158 trytes - compressed (worst): <400 trytes ## Related projects * [Ethereum virtual machine on top of Tangle](https://hackmd.io/4AqZiGdWQkuZMm1BbAI9pw) * [Implementation](https://hackmd.io/s/SJo1-IBxQ) * [Qubic: a protocol that specifies IOTA's solution for oracle machines, smart contracts, outsourced computations, etc.](https://qubic.iota.org/) * [FPGA-accelerated TrustZone-enabled IOTA Swarm Nodes](https://hackmd.io/s/Hk-5i41bm)