Firefox

AES is easier to decrypt with quantum computers, but a 256-bit key (AES-256) is still as reliable as an 128-bit key on classical computers, which is generally accepted as secure as of this writing (2016).

You can disable AES-128 and other ciphers in Mozilla Firefox, leaving all secure connections to be made with AES-256.

1. type or paste about:config in your location bar; press enter
2. click the "I'll be careful" button
3. type into search security.ssl3
4. double-click rows to turn individual options on and off
5. set the final column to 'true' if it has aes_256 in it, and false otherwise
6. visit cc.dcsec.uni-hannover.de. All of your options should have AES_256 in them.
7. you can also check out howsmyssl.com.

Chrome

For reasons explained on the Firefox page, you want to disable ciphers which might be preferred ahead of the more secure, AES-256-based ciphers.

You want to add --args --cipher-suite-blacklist=0x2B,0x2F,0xA9,0xA8 to your Chrome startup command line arguments.

Work in progress: I was not able to disable 0x2B and 0x2F? Visit cc.dcsec.uni-hannover.de and howsmyssl.com.

Help plz... I don't know how to disable different encryption ciphers on Chrome.

Tell me on GitHub Issues

iOS Safari

By default, iOS (at least on iPad) uses AES-256.

• visit cc.dcsec.uni-hannover.de. Your first cipher should have AES_256 in it.
• you can also check out howsmyssl.com.