What is the highest encryption bit that is currently usable on the latest browsers. I have seen providers issuing 128 and 256 bit certificates. Are higher bit certificates usable in browsers? Are they publicly available ? Also is 128 / 256 bit still unbreakabale based on today’s computing power ?
Thanks,
Murtaza
No, you haven’t. Not recently anyway. The key sizes in the certificates tend to be 1024, 2048 or above. (It’s not recommended to go below 2048 nowadays.)
What makes the encryption key size (128 or 256 bits) isn’t the size of the key in the certificate. The key in the certificate is used for asymmetric cryptographic, which takes place during the SSL/TLS handshake to perform an authenticated exchange of symmetric key (negotiated for this SSL/TLS session).
This symmetric key is used for encryption, and its size can indeed be 128 or 256 bits, typically. The size is dictated by the cipher suite that is negotiated (e.g. something based on AES-128 or AES-256). This key size is independent of the certificate’s key size.