From iA wiki
"Shorten", suffix: (.SHN)
Another growing and popular lossless audio format. SHN allows the use of hash files to confirm that it is an exact copy of the overall file using the MD5 digest. MD5 files are usually distributed with SHN files.
Another technology that works similarly is that of WinRAR's multimedia (both WAV and BMP) compression. While SHN is a better compression for WAV files, resulting in smaller files, they not require the download/install of new software and can also confirm file quality.