While the name sounds obscure, signapk (short for Sign APK ) plays a critical role in Android's security model. It is a command-line tool used to digitally sign Android application packages (APKs) and OTA (Over-The-Air) update ZIP files.
: The tool uses a private key (like a .pk8 file) and a certificate (like a .x509.pem file) to sign the contents of an archive. signapk
Here is the distinction: