dacskey: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/bin/dacskey - from package: dacs

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