Ключевые слова: access, attack, background, black, blackboard, board, broken, brush, brushstroke, chalk, chalkboard, concept, crack, crime, data, defend, denied, digital, drawing, education, encryption, granted, green, hack, icon, information, learn, learning, lesson, paint, paintbrush, policy, privacy, protect, protection, row, safe, safety, school, secure, security, shield, study, symbol, system, teach, technology, texture, yellow,