1: What are benefits of using HTTPS over HTTP?
HTTPS means that you tunnel the HTTP protocol over TLS/SSL which encrypts the HTTP payload.
So the benefit is that HTTP requests and responses are transmitted securely over the wire, e.g. your Internet Service Provider does not know what you’re doing.
When Google switched Gmail to use HTTPS, no additional resources were required; no network hardware, no new hosts. It only increased CPU load by about 1%.
2: How to use HTTPS?
Enable it at your endpoint, in general a web server in front of your application server. Most web servers (e.g. IIS, Apache) support this by configuration. Depending on your confidentiality requirements this may not be enough.
3: Can we use HTTPS for only login purpose and then onwords HTTP?
Technically this is possible, but it introduces some security risks. Example: After a secured login you transmit session IDs identifying the user. If you transmit those session IDs unsecurely (no SSL), session hijacking becomes a risk (‘man-in-the-middle’)
4: What settings needs to be done for making website HTTPS?
See #2. In public internet scenarios you should request (buy) a certificate from a certain Certificate Authority (CA), so that end user clients can verify whether they should trust your certificate.
5: Is there any threat present in HTTPS?
In the protocol itself there is a slight risk of man-in-the-middle attacks. E.g. a proxy between the client and server could pretend to be the server itself (this requires a successful attack to network infrastructure, e.g. DNS). There are several other ‘more obscure’ risks that do not relate to the protocol itself, e.g.:
- usage of an outdated encryption key length (e.g. 256 bit)
- loss of private keys or unappropriate key management procedures (e.g. send via unencrypted email)
- certificate authority failure
6: Is processing time required for HTTPS is greater than HTTP?
Yes, key negotiation (handshaking) requires a lot CPU capacity.
HTTP uses port 80 or 8080, while HTTPS uses TCP port 443.
The reason that some applications use 8080 (7080, 9080) instead of 80 is that on UNIX, port numbers below 1024 are reserved for super-user processes.
That’s why for OS compatibility reasons, some servers use other ports (greater than 1024). But they still have “80” inside the numner, eg. 7080, 8080, 9080.