Describe- in your own words- the mechanism for establishing a HTTPS co.docx
- 1. Describe, in your own words, the mechanism for establishing a HTTPS connection. Solution HTTPS consists of communication over HTTP (Hypertext Transfer Protocol) with an encrypted layer such as Transport Layer Security (TSL) or Secure Sockets Layer (SSL). The connection between Client and Server using HTTPS is established by a handshake process which has 3 main phases namely Hello, Certificate exchange and key exchange. a) Hello- This is the first phase where the client sends a message ClientHello which contains all the necessary information such as various cipher suites, SSL version number etc. for the server to connect to the client via SSL. Then the server responds with a ServerHello message which contains similar information for client. b) Certificate Exchange – Once the contact is established between the Server and the Client, the server has to prove its identity to the client using its SSL certificate. The SSL certificate contains various information such as name of the owner, the domain it is attached to, the certificate’s public key, certificate’s validity dates etc. The client then verifies the certificate whether it is a trusted certificate or it is verified and trusted by one of several Certificate Authorities (CAs) which client trusts. c) Key Exchange – In this phase the exchange of encryption key is happened by the client and server using a symmetric algorithm which was already agreed during the Hello phase. The client generates a random key for the symmetric algorithm. It then encrypts the key using an algorithm (which was also agreed upon during the Hello phase) and the server’s public key from the SSL certificate. Client then sends this encrypted key to the server, where it is decrypted using the server’s private key.
- 2. Once the client and server have verified each over’s identity and have secretly agreed on a key to symmetrically encrypt the data that they are about to send each other, then the HTTP requests and responses can start flowing form one party to other in the form of a plaintext message with encryption. The other party using the key decrypt is while reading.