Windows 10: Enable or Disable IDN Punycode in Firefox Address Bar in Windows

How to: Enable or Disable IDN Punycode in Firefox Address Bar in Windows

How to Enable or Disable IDN Punycode in Firefox Address Bar in Windows

Punycode is a representation of Unicode with the limited ASCII character subset used for Internet host names. Using Punycode, host names containing Unicode characters are transcoded to a subset of ASCII consisting of letters, digits, and hyphen, which is called the Letter-Digit-Hyphen (LDH) subset. Punycode is used to encode internationalized domain names (IDNs) as a defense against address spoofing.

From a security perspective, Unicode domains can be problematic because many Unicode characters are difficult to distinguish from common ASCII characters. It is possible to register domains such as "xnpple-43d.com", which is equivalent to "аpple.com". It may not be obvious at first glance, but "аpple.com" uses the Cyrillic "а" (U+0430) rather than the ASCII "a" (U+0061). This is known as a homograph attack.

Firefox allows enabling to show IDN punycode instead of non-Latin letters and Unicode symbols in the address bar. This can be very useful to help see if the currently opened web page is a phishing site or just a non-official mirror of some web site which you would like to avoid.

For more details, see also: Phishing with Unicode Domains - Xudong Zheng

This tutorial will show you how enable or disable showing IDN punycode in the address bar of Firefox for your account in Windows 7, Windows 8, and Windows 10.


EXAMPLE: IDN punycode enabled and disabled in Firefox

*note Test site: IDN Homograph Example









Here's How:

1. Open Firefox.

2. Type about:config into the address bar, press Enter, and click/tap on the I accept the risk button. (see screenshot below)



3. Type IDN_show_punycode into the search box, and press Enter. (see screenshots below step 4)

4. Double click/tap on the network.IDN_show_punycode setting to change its value to true (enable) or false (disable - default) for what you want. (see screenshots below)





5. You can now close this about:config tab if you like.


That's it,
Shawn

:)

 

Enable or Disable IDN Punycode in Firefox Address Bar in Windows


interesting post
anyone has disabled punycode ?

 

Firefox Address Bar Suggestions

I do see below

 

Firefox Address Bar Suggestions


With a brand new and previously unused Profile I do see suggestions for R, but only built-in generic Mozilla ones.

 

Firefox Address Bar Suggestions

I get no suggestions at all. I untick all those options under Address bar as well as the ones under Search. And set Firefox to delete history using custom settings for history. Never see any suggestion of any kind. So, you can get that done if thats what you want.

Bo

 

Firefox Address Bar Suggestions

I was going to suggest that too. Firefox pulls suggestions from bookmarks too, so if it's bookmarked, no amount of clearing history/etc will make it not appear.