Microsoft Challenge Handshake Authentication Protocol (MS-CHAP) is an encrypted authentication mechanism very similar to CHAP. As in CHAP, the NAS sends a challenge, which consists of a session ID and an arbitrary challenge string, to the remote client. The remote client must return the user name and an encrypted form of the challenge string, the session ID, and the MD4-hashed password. This design, which uses the MD4 hash of the password, helps provides an additional level of security because it allows the server to store hashed passwords instead of clear-text passwords or passwords that are stored using reversible encryption. MS-CHAP also provides additional error codes, including a password-expired code, and additional encrypted client-server messages that permit users to change their passwords during the authentication process. In MS-CHAP, both the client and the NAS independently generate a common initial encryption key for subsequent data encryption by MPPE.
StrongVPN is a great choice, as it meets the needs of both power users and casual users alike. Prices start at $10 a month and drop quickly, when you purchase a year of service at a time, to $5.83 a month. The ease of setup is fantastic–if you’re new to VPNs and/or don’t have extra time to fuss with manual settings, you can just download their setup app for Windows, OS X, iOS, and Android to automate the setup process. If you want a more granular control or need to manually configure devices like your router, you can follow one of their many guides for different operating systems and hardware to do it manually.
Although the diminishing online privacy of users has been a long-running theme in the digital world, the recent Facebook-Cambridge Analytica scandal was the first exposure of our fragile privacy on a global level. It is in these circumstances that the search for best VPN services has become our answer to the continually shrinking privacy and security of the average netizen.
Usually, it's the free services that throttle your usage in these ways. Some paid services will offer a trial, where you can transmit up to a certain data cap before being asked to sign up as a paying customer. That's actually pretty cool, because it gives you a chance to try out the performance of their service before paying, but it also gives the vendor a chance to make the money necessary to operate the service.
Password Authentication Protocol (PAP) is a clear-text authentication scheme. The NAS requests the user name and password, and PAP returns them in clear text (unencrypted). Obviously, this authentication scheme is not secure because a malicious user could capture the user's name and password and use it to get subsequent access to the NAS and all of the resources provided by the NAS. PAP provides no protection against replay attacks or remote client impersonation once the user's password is compromised.
IPSec NAT-T enables IPSec peers to negotiate and communicate when they are behind a NAT. To use IPSec NAT-T, both the remote access VPN client and the remote access VPN server must support IPSec NAT-T. IPSec NAT-T is supported by the Windows Server 2003 Microsoft L2TP/IPSec VPN Client and by the L2TP/IPSec NAT-T Update for Windows XP and the L2TP/IPSec NAT-T Update for Windows 2000. During the IPSec negotiation process, IPSec NAT-T-capable peers automatically determine whether both the initiating IPSec peer (typically a client computer) and responding IPSec peer (typically a server) can perform IPSec NAT-T. In addition, IPSec NAT-T-capable peers automatically determine if there are any NATs in the path between them. If both of these conditions are true, the peers automatically use IPSec NAT-T to send IPSec-protected traffic.
You heard us right on that last bit: a number of VPN providers have systems in place where they will accept gift cards from major retailers (that are totally unrelated to their business) like Wal-Mart or Target in exchange for VPN credit. You could buy a gift card to any number of big box stores using cash, redeem it for VPN credit, and avoid using your personal credit card or checking information.
The country connections, meanwhile, matter most to those who want to spoof their location; however, non-spoofers should also make sure there are connections in their home country. If you live in Los Angeles, for example, and want access to American content, then you’ll need a VPN that provides U.S. connections. It won’t work to try and watch Amazon Prime Video over a Dutch VPN connection, because as far as Hulu’s concerned your computer is in the Netherlands.

First and foremost, using a VPN prevents anyone on the same network access point (or anywhere else) from intercepting your web traffic in a man-in-the-middle attack. This is especially handy for travelers and for those using public Wi-Fi networks, such as web surfers at hotels, airports, and coffee shops. Someone on the same network, or the person in control of the network you're using, could conceivably intercept your information while you're connected.