vlock binary package in Ubuntu Focal riscv64

 vlock either locks the current terminal (which may be any kind of terminal,
 local or remote), or locks the entire virtual console system, completely
 disabling all console access. vlock gives up these locks when either the
 password of the user who started vlock or the root password is typed.
 .
 vlock is interesting on multi user system environments. vlock allows users
 to lock their sessions while other users can still use the same system via
 other virtual terminal.
 .
 vlock is very useful for users security.

Source package