curl - Is data encrypted when using the --insecure option?
Yes, the transfered data is still sent encrypted. -k/--insecure will "only make" curl skip certificate validation, it will not turn off SSL all together.
More information regarding the matter is available under the following link:
It will be encrypted but insecure. If you trust the certificate you should add the certificate to your certificate store instead of connecting insecurely.
macOS: sudo security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain ~/new-root-certificate.crt
Ubuntu, Debian: sudo cp foo.crt /usr/local/share/ca-certificates/foo.crtsudo update-ca-certificates
CentOS 6:yum install ca-certificatesupdate-ca-trust force-enablecp foo.crt /etc/pki/ca-trust/source/anchors/update-ca-trust extract
CentOs 5:cat foo.crt >>/etc/pki/tls/certs/ca-bundle.crt
Windows:certutil -addstore -f "ROOT" new-root-certificate.crt