How do you optimize TLS performance for mobile devices and low-bandwidth networks?

1 Choose the right TLS version and cipher suite

TLS has evolved over the years, with newer versions offering better security and performance features. The latest version, TLS 1.3, reduces the number of round trips required for the handshake, supports only strong cipher suites, and enables faster resumption of connections. You should always use the highest TLS version supported by your server and client, and avoid deprecated or insecure versions like SSL or TLS 1.0. You should also choose a cipher suite that matches your security and performance needs. For example, you can use elliptic curve cryptography (ECC) to reduce the key size and computation time, or use AES-GCM to enable hardware acceleration and parallel processing.

3 Minimize the number of TLS connections and requests

Each TLS connection requires a handshake, which consumes network bandwidth and CPU resources. To optimize the performance, you should minimize the number of TLS connections and requests you make. You can do this by using techniques such as HTTP/2, connection pooling, keep-alive, multiplexing, and caching. HTTP/2 is a protocol that allows multiple requests and responses to be sent over a single TLS connection, using binary framing and header compression. Connection pooling is a technique that reuses existing TLS connections for multiple requests, instead of creating new ones. Keep-alive is a feature that prevents the connection from closing after each request, and allows it to be reused for subsequent requests. Multiplexing is a technique that allows multiple requests to be sent and received concurrently over a single connection, without blocking each other. Caching is a technique that stores the responses locally, either on the client or on an intermediate proxy, and avoids sending unnecessary requests to the server.

4 Optimize the TLS certificates and validation

TLS certificates are digital documents that verify the identity and authenticity of the server and the client. They are also used to establish the encryption keys for the data exchange. However, certificates can also affect the performance of TLS, depending on their size, chain length, and validation process. To optimize the performance, you should use certificates that are as small as possible, without compromising the security. You should also use certificates that have a short chain length, meaning that they have fewer intermediate certificates between the root certificate and the end-entity certificate. This can reduce the size of the certificate message and the number of validation steps. You should also use certificates that are valid and trusted by the client, and avoid self-signed or expired certificates that can trigger warnings or errors.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?