knsec3hash: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/knsec3hash - from package: knot

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/knsec3hash - from package: knot

You may install the required package with command apt-get install {package}

Error in other languages:
knsec3hash: bevel nie gevind nie
knsec3hash: comandă negăsită
knsec3hash: comando não encontrado
knsec3hash: commande introuvable
knsec3hash: command not found
knsec3hash: käsku ei ole
knsec3hash: không tìm thấy lệnh
knsec3hash: komanda nerasta
knsec3hash: Kommando nicht gefunden.
knsec3hash: kommandot finns inte
knsec3hash: komut yok
knsec3hash: nie znaleziono polecenia
knsec3hash: níor aimsíodh an t-ordú
knsec3hash: no se encontró la orden
knsec3hash: no s'ha trobat l'ordre
knsec3hash: opdracht niet gevonden
knsec3hash: parancs nem található
knsec3hash: perintah tidak ditemukan
knsec3hash: príkaz nenájdený
knsec3hash: příkaz nenalezen
knsec3hash: команда не найдена
knsec3hash: командата не е открита
knsec3hash: 命令找不到
knsec3hash: コマンドが見つかりません