--- title: "NTP Authentication sub-tab" slug: "ntp-authentication-sub-tab" updated: 2024-10-16T11:17:51Z published: 2024-10-16T11:17:51Z canonical: "docs.zpesystems.com/ntp-authentication-sub-tab" --- > ## Documentation Index > Fetch the complete documentation index at: https://docs.zpesystems.com/llms.txt > Use this file to discover all available pages before exploring further. # NTP Authentication sub-tab NTP reduces security risks associated with time synchronization. With authentication, there is assurance a generated response is from an expected source (rather than maliciously generated or intercepted). Authentication applies a list of agreed keys (passwords) between a server and a client. Communication between server and client is encrypted with one of the agreed keys appended to the messages. The appended key is un-encrypted to ensure it matches one of the agreed keys. Only then is action taken. ![](https://cdn.document360.io/763c5fb1-b9af-4ccd-9ad6-cf28ae4cd5a3/Images/Documentation/image-1678297646659.png) ### Configure Key Number Set This requires Admin privileges. Repeat the process for each key number set. 1. Go to *System :: Date and Time :: NTP Authentication*. 2. Click **Add** (displays dialog). ![](https://cdn.document360.io/763c5fb1-b9af-4ccd-9ad6-cf28ae4cd5a3/Images/Documentation/image-1678297799245.png) 3. Enter **Key Number** (any unsigned integer (range: 1 to 232 – 1). 4. On **Hash Algorithm** drop-down, select one (MD5, RMD160, SHA1, SHA256, SHA384, SHA512, SHA3-224, SHA3-256, SHA3-384, SHA3-512). 5. Enter **Password** character string (space character not allowed). Alternatively, enter a hexadecimal number with prefix **HEX** followed by the number ######. 6. Click **Save**. ### Delete Key Number 1. Go to *System :: Date and Time :: NTP Authentication*. 2. Select checkbox next to Key Number to delete. 3. Click **Delete**. ### Link the NTP server and Key Number 1. Go to *System :: Date and Time :: Local Settings*. 2. Use separator '|' (pipe) between server address and its key number. ![](https://cdn.document360.io/763c5fb1-b9af-4ccd-9ad6-cf28ae4cd5a3/Images/Documentation/image-1678297769321.png) > [!NOTE] > NOTE > > You can also add multiple NTP servers in the Server field. Enter comma-separated values without spaces. 3. Make changes, as needed. 4. Click **Save**.