What is SSL and How Does It Work?
In this blog, we will provide a complete guide on what SSL is and how it works. In the present day, online security is one of the most important aspects of internet use. SSL Certificates are becoming a key factor in protecting private data passed over the internet. Whenever you browse your favorite e-commerce website, use an online banking account, or enter personal information on a form, SSL is essential for keeping your data private and secure.
Understanding SSL
SSL stands for Secure Socket Layer. It’s a secure data protocol designed for a secure connection between a web server and a web browser. SSL ensures secret communication, ensuring that the data exchanged between the two parties is kept confidential and relevant.
How Does SSL Work?
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Handshake Protocol
The SSL handshake is the first step in creating a secure connection between the client (web browser) and the server. It involves the following steps:
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Client Hello
The process starts when the client sends a “Hello” message to the server, indicating the client’s desire to establish a secure connection. The message includes the SSL/TLS version, cipher suites, and other parameters.
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Server Hello
In response, the server sends a “Hello” message back to the client. The server agrees to the secure connection request and selects the SSL/TLS version and cipher suite for the connection.
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Certificate Exchange
Following the “Hello” messages, the server sends its SSL certificate to the client. This certificate includes the public key, digital signature, and other identifying information. The client verifies the certificate’s authenticity and validity, ensuring it has been issued by an authorized Certificate Authority (CA).
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Key Exchange
One of the most crucial steps in the SSL handshake is the key exchange. The client and server exchange keys and generate a new shared secret key, which will be used to encrypt and decrypt data during the session.
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Generate Session Keys
Once the shared secret key has been established, both parties use it to generate session keys for encrypting and decrypting information during the SSL session.
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Security and Data Transfer
After the SSL handshake is complete and a secure connection is established, data transfer between the client and server begins. During this step, all data sent over the connection is protected with symmetric encryption techniques such as AES (Advanced Encryption Standard) or 3DES. This encryption ensures that even if intercepted, the data is unreadable to unauthorized parties.
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Data Security and Authentication
In addition to data security, SSL involves mechanisms to authenticate the identities of the communicating parties:
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Data Security
SSL uses hash functions like SHA-256 (Secure Hash Algorithm 256-bit) to verify the integrity of transmitted data. These hashes are sent alongside the data and used to confirm its accuracy upon receipt. If the hashes do not match, it indicates potential tampering.
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Authentication
SSL authentication verifies the identity of the web server. When a server presents its SSL certificate during the handshake, the client verifies its authenticity by checking the digital signature and the chain of trust back to a trusted root CA.
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Termination and Session Closing
Once the SSL session is finished or terminated, the client and server connection is properly closed. The exchange of “Close Notify” messages indicates the end of the session. Both parties stop sending data and release any resources allocated to the SSL session.
Conclusion
In conclusion, this guide has covered what SSL is and how it works. SSL is crucial for securing data exchanges between websites and browsers. SSL establishes secure connections through steps in the handshake protocol, safeguarding data exchanged between parties. Key exchange and session key generation are essential for maintaining data security. SSL also employs various mechanisms for data protection and server authentication. Through these comprehensive steps, SSL ensures data security via hashing functions and verifies server identities.