Example

Figure 3.5 shows a typical Telnet session involving data encryption in one direction.

1a),2a)

Initial negotiation to use the ENCRYPT option. (Host 2 wants Host 1 to send encrypted data).

2b)

Host 2 sends the list of supported encryption types.

2c)

Host 2 requests Host 1 to begin encrypting its data stream with encryption type 1.

1b)

Host 1 selects encryption type 2 as it did not support the requested type. All data following the IAC SE sequence in this command are now encrypted.

2d)

Host 2 has received all the information which needed to be encrypted, and requests Host 1 to stop encrypting.

1c)

Host 1 informs Host 2 that the encryption is being turned off after the IAC SE sequence in this message.

  
Figure 3.5: Example of a session with encryption