A GSM-Based Protocol for Expanding Blockchain Accessibility

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STKS2Chain is a protocol designed to bridge GSM technologies with blockchain systems. It leverages the ubiquitous nature of SIM cards and SMS messaging to enable seamless transactions, wallet management, and smart contract interactions without requiring an internet connection. At its core, STK2Chain allows users to perform blockchain-based operations via familiar mobile interfaces such as STK menus, making blockchain more accessible to underserved demographics and areas with limited internet access.

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How it works

graph LR
  A(Start)

    A[STK Menu] --> B["GSM Tower Network
    (Carrier BTS)"]
    B --> C["STK2Chain Middleware
    (ERC-4337 Bundler)"]
    C --> D["Ethereum Node
    (ERC-4337 EntryPoint)"]
    D -->|TX Hash| C
    C -->|SMS Confirm| A

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eSIM Profile Architecture

┌───────────────────────────┐
│   eSIM Profile Elements   │
│───────────────────────────│
│  • eUICC Network Config   │
│  • STK Interface          │
│    └ Java Card Applet     │
│  • HD Wallet [stk2wallet] │
└───────────────────────────┘



┌──────────────────────────────┐
│       eSIM Profile (TEE)     │
│──────────────────────────────│
│ 1. eUICC (Secure Element)    │ ← Hardware root of trust
│ 2. Java Card Applet          │ ← Isolated execution
│ 3. ERC-4337 Wallet Logic     │ ← Code integrity
└──────────────────────────────┘