: An alphanumeric code used by a specific organization, researcher, or online community to label private data.

: In some file-sharing circles, random strings are used to prevent automated copyright flagging.

Without more context, it is difficult to provide a "long paper" on this specific topic. It most likely refers to one of the following:

: Segmented RAR files (e.g., .part1, .part2) are commonly used to distribute high-definition video files, large software packages, or games over the internet.