A few days ago, I helped my grandmother sort through some old boxes and found her dowry from the Song Dynasty, a silk handkerchief with embroidered camellias and butterflies. My grandmother said this handkerchief is remarkable because it hides her identity in the details. Each weft thread of the camellia petals is woven in segments, and even the gradient of the gold thread on the butterfly's wings is perfect. The most amazing part is that in the corner, there’s a super tiny character "沈" as a signature, which you have to get really close to see. My grandmother said that in the past, this was how they identified their own belongings, and others couldn't replicate it. Speaking of this, it reminds me of the troubles in the digital world: during the last online class, the teacher mistook my virtual avatar for another student's because we looked too similar. And for the digital collectibles I bought, I wanted to prove they were mine, but there was no reliable way to do so. I always felt...