Ключевые слова: accept, address, background, barcode, bill, bit, blockchain, cashless, code, coding, coin, cold, concept, crypto, cryptocurrency, cryptography, currency, digital, eth, ethereum, internet, internet of things, key, mobile, money, non cash, online, paper, pay, payment, phone, qr, qr code, qrcode, reader, receipt, scan, scanner, scanning, screen, shop, shopping, smart, smartphone, society, symbol, technology, transaction, virtual, wallet,