test update

ESP/ESP_Start/README.md

@@ -1,63 +1,3 @@
-# ESP Start — Solution
+# test
 
-**Difficulty:** Easy | **Category:** ESP | **Flag:** `ESPILON{st4rt_th3_w1r3}`
+hello world
-
-## Overview
-
-Flash the provided firmware onto an ESP32. On boot, the device outputs an
-XOR-encrypted flag along with the XOR key via UART at 115200 baud.
-
-## Step 1 — Flash the firmware
-
-```bash
-esptool.py --chip esp32 --port /dev/ttyUSB0 --baud 460800 write_flash -z \
-    0x1000  bootloader.bin \
-    0x8000  partition-table.bin \
-    0x10000 hello-espilon.bin
-```
-
-## Step 2 — Read the UART output
-
-```bash
-screen /dev/ttyUSB0 115200
-# Or:
-minicom -D /dev/ttyUSB0 -b 115200
-```
-
-The device prints:
-
-```text
-=== Hello ESP ===
-System ready.
-
-Encrypted flag: 09 12 19 07 00 0E 07 35 3F 35 7D 3C 38 1E 3D 26 7F 1E 3E 7F 3E 72 34
-XOR Key: 4C 41 49 4E
-```
-
-## Step 3 — Decrypt the flag
-
-XOR key is `LAIN` (`4C 41 49 4E`). Apply it cyclically:
-
-```python
-enc = bytes([0x09,0x12,0x19,0x07,0x00,0x0E,0x07,0x35,
-             0x3F,0x35,0x7D,0x3C,0x38,0x1E,0x3D,0x26,
-             0x7F,0x1E,0x3E,0x7F,0x3E,0x72,0x34])
-key = b"LAIN"
-flag = bytes(b ^ key[i % len(key)] for i, b in enumerate(enc))
-print(flag.decode())
-# ESPILON{st4rt_th3_w1r3}
-```
-
-## Key Concepts
-
-- **ESP32 flashing**: `esptool.py` writes bootloader, partition table, and application at their respective offsets
-- **UART monitoring**: ESP32 default baud rate is 115200, 8N1
-- **XOR cipher**: Simple symmetric cipher — key is broadcast in plaintext here as an intro challenge
-
-## Flag
-
-`ESPILON{st4rt_th3_w1r3}`
-
-## Author
-
-Eun0us