使用javascript创建新的文本文件（）但存储[objectFile]而不是文本

I'm working on a project to encrypting data and sent it to the server, so I need to store the data in a file and then sent it to the server(php). the user then grab the file on the client side to decrypt it. But I'm runing into the problem of storing the data in the text file or open it.I'm working on a project to encrypting data and