URL Encryption™ FAQ

What is URL Encryption™?

URL Encryption encrypts web site addresses (URLs) so that only the Anonymizer can read them. When you use Anonymizer Surfing normally (without URL Encryption), web site addresses look something like this:

However, surfing with URL Encryption renders the URL of the sites you are visiting unintelligible:

Why is this useful?

Requests to load a page anonymously are sent by your web browser to our Anonymizer servers. Unless you are using our SSH Tunneling service, these requests travel over the Internet "in the clear" (as plain text). Thus, it is possible for your ISP, network administrator, or other intermediary to easily log the sites that you visit. URL Encryption™ prevents this invasion of privacy by rendering the URLs of the web sites you visit meaningless to outside observers.

Who can use URL Encryption™?

All of our Anonymous Surfing subscribers.

How do I use URL Encryption™?

To enable it when you log in, click the "URL Encryption on" button on the Members Login Page. You can toggle URL Encryption on and off at any time while you are surfing via the "Control Panel" button on the Anonymizer bar included at the top of each page you visit. URL Encryption is toggled on the Control Panel by the "URL Encryption on/off" radio button.

Why does URL Encryption™ require cookies?

Because there is no other way for the Anonymizer to keep track of who has URL Encryption turned on or off. Our users are anonymous, after all! If you examine the cookie set for URL Encryption, you will see that it contains no identifying information about you whatsoever. It carries only the value URL_Encryption=On or URL_Encryption=Off. For more information about cookies, Cookie Central is an excellent resource. Remember that the Anonymizer still stops all cookies by default; unless you're using Safe Cookies™, we never let cookies from the sites you visit through.

Can I use bookmarks with URL Encryption™?

Yes.

What is to prevent an intermediary (or other adversary) from getting an Anonymizer account so as to be able to decrypt my Encrypted URLs?

The algorithm used for URL Encryption encrypts URLs differently for each one of our users. Thus, there is no way for anyone else to decrypt your URLs short of stealing your password and logging into your account.

Why are Encrypted URLs longer than their plaintext counterparts?

The short answer is: so that the same URL never encrypts the same way in two browsing sessions. If you're familiar with cryptography, the technical answer is: we encrypt in CBC mode; the "extra" length you see is the Initialization Vector.

How secure is URL Encryption?

URL encryption uses 128-bit Blowfish, an algorithm and keylength considered to be strong enough that it would be foolish for anyone to attempt to break it by brute force. It would be far easier for someone to "bug" your computer or try to infer the URL from the content of the pages you request than to break the encryption. (Using Secure Tunneling prevents such snooping). The bottom line: URL Encryption protects against the common forms of logging and request snooping employed by ISPs and other intermediaries.