Hi Dan,
Yes, ibm_db supports secure connection to DB2 over SSL same as ODBC/CLI driver. If you have SSL Certificate from server or an CA signed certificate, just use it in connection string as below:
ibmdb.open("DRIVER={DB2};DATABASE=<dbname>;HOSTNAME=<myhost>;UID=db2user;PWD=password;PORT=<dbport>;PROTOCOL=TCPIP;Security=SSL;SSLServerCertificate=<cert.arm file path>", function(...
Thanks and Regards,
Bimal Jha