A mix of features and price make a good VPN, but plenty of bad VPNs masquerade as good ones. Look for articles written by trustworthy sources that discuss the merits of each service based on its features, versus simple rundowns and user testimonials, which are almost always polluted by a combination of fanatical users and corporate bootstrapping in attempt to get their names out to potential customers.
With the increasing use of VPNs, many have started deploying VPN connectivity on routers for additional security and encryption of data transmission by using various cryptographic techniques.[33] Home users usually deploy VPNs on their routers to protect devices, such as smart TVs or gaming consoles, which are not supported by native VPN clients. Supported devices are not restricted to those capable of running a VPN client.[34]
We used to advise people to do banking and other important business over their cellular connection when using a mobile device, since it is generally safer than connecting with a public Wi-Fi network. But even that isn't always a safe bet. Researchers have demonstrated how a portable cell tower, such as a femtocell, can be used for malicious ends. The attack hinges on jamming the LTE and 3G bands, which are secured with strong encryption, and forcing devices to connect with a phony tower over the less-secure 2G band. Because the attacker controls the fake tower, he can carry out a man-in-the-middle attack and see all the data passing over the cellular connection. Admittedly, this is an exotic attack, but it's far from impossible.

When we test VPNs, we try to get a sense for the impact a service has on internet performance by finding a percentage change between using the VPN and not using the VPN for several speed measurements. First, we run several tests without the VPN active, discard the highest and lowest results, and find the average of what remains. This is our baseline. We then do the same thing, but with the VPN active.

Each of these VPN scenarios can be deployed to provide connectivity over a public network, such as the Internet, or over a private intranet. VPN connections can also be deployed in an extranet scenario to communicate securely with business partners. An extranet functions as an intranet that can be securely shared with a designated business partner.

Latency: This is closely tied to proximity, but is also affected by the amount of traffic on the networks between you and the VPN server. Latency measures the time it takes to send and receive a request from a server, also called ping time. Many VPN apps will allow you to see which server offer the least latency, usually measured in milliseconds. If not, you can connect to the server and use a terminal or command prompt to ping a website and view the time.
The user’s certificate could be stored on the VPN client computer or in an external smart card. In either case, the certificate cannot be accessed without some form of user identification (PIN number or name/password credentials) between the user and the client computer. This approach meets the something-you-know-plus-something-you-have criteria recommended by most security experts.
For the formal testing, we used an HP EliteBook X360 1020 G2 notebook, an Asus ZenPad S8 tablet (for Avira Phantom VPN) and a Samsung Galaxy Note 8 phone (for Speedify). Wi-Fi and Ethernet connections were provided by a 200-Mbps cable broadband line. Each time we connected to a VPN service, we recorded how long it took to get online and noted how many times the service disconnected us.
However, if you’re using a top-tier VPN service, the difference in speed usually isn’t noticeable, and can sometimes speed up your connection. You can still watch streaming videos and download large files without interruption. Our VPN servers are among the fastest in the industry and we work hard to keep it that way. Download Hotspot Shield VPN and get privacy protection without sacrificing speed.
IPVanish is one of the very best and reliable VPN service providers with an extensive range of VPN servers in more than 60 countries. The wide range of server availability (more than 500 servers) makes their credibility stronger to be in the fastest VPN service provider list. IPVanish is also known as a Tier-1 VPN provider with all the required and advanced VPN features to offer. As a fast VPN option, it offers unlimited bandwidth that is best for all streaming lovers and other netizens. Not only this, but IPVanish has some remarkable features like KillSwitch, unlimited server switching and automatic IP-scrambler that makes a fast VPN connection. With IPVanish you can get your money back within 7 days in case you are not fully satisfied with their fast VPN connection. Here is the VPN speed test result for IPVanish:

For the Routing and Remote Access service, MPPE encryption strengths are configured on the Encryption tab on the properties of a remote access policy to use 40-bit (the Basic setting), 56-bit (the Strong setting), or 128-bit (the Strongest setting) encryption keys. Administrators should use 40-bit MPPE encryption keys to connect with older operating systems that do not support 56-bit or 128-bit encryption keys (this includes older Windows operating systems and operating systems from companies other than Microsoft). Otherwise, use 128-bit encryption keys. Encryption strengths for L2TP/IPSec connections use 56-bit DES (the Basic or Strong setting) or 168-bit 3DES (the Strongest setting).
So, having stated that, there are VPN protocols that are fast (implies no, or minimum encryption) and some are slow (implies stronger encryption). PPTP is a protocol which is one of the less secure but fastest protocols out there. Similarly, other protocols such as OpenVPN or L2TP/IPSec are way more secure. So, it all comes down to your own priorities. Do you want more speed or more protection? And if you want best of both worlds, we have already suggested Fast VPN providers that have all the options and protocols to get accustomed to your priorities.
We’ll get to the implications of a VPN’s location in a moment, but first, let’s get back to our secure tunnel example. Once you’re connected to the VPN and are “inside the tunnel,” it becomes very difficult for anyone else to spy on your web-browsing activity. The only people who will know what you’re up to are you, the VPN provider (usually an HTTPS connection can mitigate this), and the website you’re visiting.
Many VPN services also provide their own DNS resolution system. Think of DNS as a phone book that turns a text-based URL like "pcmag.com" into a numeric IP address that computers can understand. Savvy snoops can monitor DNS requests and track your movements online. Greedy attackers can also use DNS poisoning to direct you to bogus phishing pages designed to steal your data. When you use a VPN's DNS system, it's another layer of protection.