QIE uses apache camel to perform all of the FTP/SFTP operations. To adjust the logging level for all of the QIE libraries including the apache camel libraries, you will need to update the system configuration 'Log Level' option to 'Info'. This option can be found in the 'Other System Settings' area of the 'Advanced' system configuration.
Once this has been updated, you will be able to see log entries in your QIE installation logs directory (in windows this defaults to 'C:\ProgramData\QIE\logs'. The file will be 'qie.log' and will contain some lines that look like:
2017-07-06 09:25:56,406 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> Local version string: SSH-2.0-JSCH-0.1.54
2017-07-06 09:25:56,406 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> CheckCiphers: aes256-ctr,aes192-ctr,aes128-ctr,aes256-cbc,aes192-cbc,aes128-cbc,3des-ctr,arcfour,arcfour128,arcfour256
2017-07-06 09:25:56,407 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> aes256-ctr is not available.
2017-07-06 09:25:56,407 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> aes192-ctr is not available.
2017-07-06 09:25:56,407 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> aes256-cbc is not available.
2017-07-06 09:25:56,407 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> aes192-cbc is not available.
2017-07-06 09:25:56,407 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> CheckKexes: diffie-hellman-group14-sha1,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521
2017-07-06 09:25:56,430 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> diffie-hellman-group14-sha1 is not available.
2017-07-06 09:25:56,430 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> CheckSignatures: ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
2017-07-06 09:25:56,430 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> SSH_MSG_KEXINIT sent
2017-07-06 09:25:56,430 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> SSH_MSG_KEXINIT received
2017-07-06 09:25:56,430 [Test Mapping Function Runner] INFO org.apache.camel.component.file.remote.SftpOperations - JSCH -> kex: server: curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,
Specifically you will look for the lines that contain 'org.apache.camel' for the log entries that are ouput from the SFTP operation.