You can also write an encryption method yourself.

For example, using unicode character encryption. Suppose the unicode value of the number a is 1234. You design a function yourself, such as y = 2x 3+3, to get a new unicode character, and then convert this unicode character into a letter. This letter may be a Chinese character, but it is more likely to be a foreign symbol. Anyway, most people won't recognize it. When decrypting, just push it back.