wpa technology. Encryption technologies and algorithms. Wireless network encryption type: how to choose a security method

Today, many people have a Wi-Fi router at home. After all, wirelessly it is much easier to connect to the Internet a laptop, a tablet, and a smartphone, of which there are more than people in every family. And it (the router) is essentially the gateway to the information universe. Read the front door. And it depends on this door whether an uninvited guest will come to you without your permission. Therefore, it is very important to pay attention to the correct configuration of the router so that your wireless network is not vulnerable.

I don’t think I need to remind you that hiding the access point’s SSID does not protect you. Restricting access by MAC address is not effective. Therefore, only modern encryption methods and a complex password.

Why encrypt? Who needs me? I have nothing to hide

It’s not so scary if they steal the PIN code from your credit card and withdraw all the money from it. Moreover, if someone surfs the Internet at your expense, knowing the Wi-Fi password. And it’s not so scary if they publish your photos from corporate parties where you look unsightly. It’s much more offensive when attackers get into your computer and delete photos of how you picked up your son from the maternity hospital, how he took his first steps and went to first grade. Backups are a separate topic, of course they need to be done... But over time, your reputation can be restored, you can earn money, but the photographs that are dear to you are no longer there. I think everyone has something that they don't want to lose.
Your router is a border device between private and public, so make sure it is fully protected. Moreover, it is not so difficult.

Encryption technologies and algorithms

I'm leaving out the theory. It doesn’t matter how it works, the main thing is to know how to use it.
Wireless security technologies developed in the following chronological order: WEP, WPA, WPA2. Encryption methods RC4, TKIP, AES have also evolved.
The best in terms of security today is the WPA2-AES combination. This is exactly how you should try to configure Wi-Fi. It should look something like this:

WPA2 has been mandatory since March 16, 2006. But sometimes you can still find equipment that does not support it. In particular, if you have Windows XP installed on your computer without the 3rd service pack, then WPA2 will not work. Therefore, for reasons of compatibility, on routers you can find configuration options WPA2-PSK -> AES+TKIP and another menagerie.
But if your fleet of devices is modern, then it is better to use WPA2 (WPA2-PSK) -> AES, as the most secure option today.

What is the difference between WPA(WPA2) and WPA-PSK(WPA2-PSK)

The WPA standard provides the Extensible Authentication Protocol (EAP) as the basis for the user authentication mechanism. An indispensable condition for authentication is the presentation by the user of a certificate (otherwise called a credential) confirming his right to access the network. To obtain this right, the user is verified against a special database of registered users. Without authentication, the user will be prohibited from using the network. The registered user base and verification system in large networks are usually located on a special server (most often RADIUS).
Simplified Pre-Shared Key mode (WPA-PSK, WPA2-PSK) allows you to use one password, which is stored directly in the router. On the one hand, everything is simplified, there is no need to create and maintain a user base, on the other hand, everyone logs in with the same password.
At home, it is more advisable to use WPA2-PSK, that is, the simplified mode of the WPA standard. Wi-Fi security does not suffer from this simplification.

Wi-Fi access password

Everything is simple here. The password for your wireless access point (router) must be more than 8 characters and contain letters in different case, numbers, and punctuation marks. And he should not be associated with you in any way. This means that dates of birth, your names, car numbers, phone numbers, etc. cannot be used as a password.
Since it is almost impossible to break WPA2-AES head-on (there were only a couple of cases simulated in laboratory conditions), the main methods of cracking WPA2 are a dictionary attack and brute force (sequential search of all password options). Therefore, the more complex the password, the less chance attackers have.

... in the USSR, automatic storage lockers became widespread at railway stations. The lock code was one letter and three numbers. However, few people know that the first version of storage lockers used 4 digits as a code combination. What difference would it seem? After all, the number of code combinations is the same - 10,000 (ten thousand). But as practice has shown (especially the Moscow Criminal Investigation Department), when a person was asked to use a combination of 4 digits as a password to a storage locker cell, a lot of people used their year of birth (so as not to forget). What the attackers used quite successfully. After all, the first two digits in the date of birth of the absolute majority of the country's population were known - 19. All that remains is to determine by eye the approximate age of the baggage check-in person, and any of us can do this with an accuracy of +/- 3 years, and the remainder we get (more precisely, the attackers) is less 10 combinations for selecting an access code to an automatic storage locker...

Security rules when creating a password

To each his own. That is, the router password should not match any other password you have. From mail, for example. Make it a rule that all accounts have their own passwords and they are all different.
Use strong passwords that cannot be guessed. For example: 2Rk7-kw8Q11vlOp0

The Wi-Fi password has one huge advantage. You don't need to remember it. You can write it on a piece of paper and stick it to the bottom of the router.

Guest Wi-Fi zone

If your router allows you to organize a guest area. Then be sure to do it. Naturally protecting it with WPA2 and a strong password. And now, when friends come to your home and ask for Internet access, you don’t have to tell them your main password. Moreover, the guest zone in routers is isolated from the main network. And any problems with your guests' devices will not affect your home network.

The network security key is a password that you can use to connect to a working Wi-Fi network. The secure operation of a wireless network directly depends on it. Its main task is to protect the Wi-Fi user (owner) from unauthorized connection to it. Some may think that such a connection, in general, will not interfere much with working on the Internet. In fact, it is fraught with a significant decrease in Internet speed. Therefore, the closest attention must be paid to creating a password.

In addition to the actual complexity of the password being created, the degree of security of a Wi-Fi wireless network is largely influenced by the type of data encryption. The importance of the type of encryption is explained by the fact that all data transmitted within a particular network is encrypted. Such a system allows you to protect yourself from unauthorized connections, because without knowing the password, a third-party user using his device simply will not be able to decrypt the data transmitted within the wireless network.

Types of network encryption

Currently, Wi-Fi routers use three different types of encryption.

They differ from each other not only in the number of characters available to create a password, but also in other equally important features.

The weakest and least popular type of encryption today is WEP. In general, this type of encryption has been used before and is now rarely used. And this is not just a matter of obsolescence of this type of encryption. He's really quite unreliable. Users using WEP-encrypted devices have a fairly high chance of having their own network security key hacked by a third party. This type of encryption is not supported by many modern Wi-Fi routers.

The last two types of encryption are much more secure and are much more commonly used. At the same time, users have the opportunity to choose the level of network security. Thus, WPA and WPA2 support two types of security checks.

One of them is designed for ordinary users and contains one unique password for all connected devices.

The other is used for businesses and significantly improves the reliability of the Wi-Fi network. Its essence is that each individual device creates its own unique security key.

Thus, it becomes almost impossible to connect to someone else's network without permission.

However, when choosing your future router, you should choose exactly the model that supports WPA2 encryption. This is explained by its greater reliability compared to WPA. Although, of course, WPA encryption is quite high quality. Most routers support both of these types of encryption.

How to find out your Wi-Fi network security key

You can use several methods to find out your wireless network security key.

There are many dangerous risks associated with wireless protocols and encryption methods. Thus, the robust design of various wireless security protocols is used to minimize them. These wireless security protocols provide prevention of unauthorized access to computers by encrypting transmitted data on a wireless network.

Difference between WPA2, WPA, WEP Wi-Fi protocols

Most wireless access points have the option to enable one of three wireless encryption standards:

WEP (Wired Equivalent Privacy)
WPA2

WEP or Wired Equivalent Privacy

The first wireless security network was WEP or Wired Equivalent Privacy protocol. It started with 64-bit encryption (weak) and eventually went all the way to 256-bit encryption (strong). The most popular implementation in routers is still 128-bit encryption (in-between). This was considered as a possible solution until security researchers discovered several vulnerabilities in it, allowing hackers to crack the WEP key within minutes. He used CRC or Cyclic Redundancy Check.

WPA or Wi-Fi Protected Access

To address the shortcomings of WEP, WPA was developed as a new security standard for wireless protocols. To ensure message integrity, he used integrity protocolTKIP or Temporal Key Integrity. This was different from WEP in some ways, which used CRC or Cyclic Redundancy Check. TKIP was thought to be much stronger than CRC. Its use ensured that each data packet was transmitted using a unique encryption key. The key combination increased the difficulty of decoding the keys and thereby reduced the number of intrusions from outside. However, like WEP, WPA also had a disadvantage. Thus, WPA was extended in WPA 2.

WPA2

WPA 2 is currently recognized as the most secure protocol. One of the most important changes visible between WPA and WPA2 is the mandatory use of algorithms AES (Advanced Encryption Standard) and introduction CCMP (Counter Cipher Mode with Blockchain Authentication Code Protocol) as a replacement for TKIP. CCM mode combines Confidentiality Mode (CTR) and Chain Code Authentication (CBC-MAC) for authentication. These modes have been widely studied and have proven to have well-understood cryptographic properties that provide good security and performance in software or hardware today.

Recently, many “revealing” publications have appeared about the hacking of some new protocol or technology that compromises the security of wireless networks. Is this really so, what should you be afraid of, and how can you ensure that access to your network is as secure as possible? Do the words WEP, WPA, 802.1x, EAP, PKI mean little to you? This short overview will help bring together all the encryption and radio access authorization technologies used. I will try to show that a properly configured wireless network represents an insurmountable barrier for an attacker (up to a certain limit, of course).

Basics

Any interaction between an access point (network) and a wireless client is based on:

Authentication- how the client and the access point introduce themselves to each other and confirm that they have the right to communicate with each other;
Encryption- what scrambling algorithm for transmitted data is used, how the encryption key is generated, and when it changes.

The parameters of a wireless network, primarily its name (SSID), are regularly advertised by the access point in broadcast beacon packets. In addition to the expected security settings, requests for QoS, 802.11n parameters, supported speeds, information about other neighbors, etc. are transmitted. Authentication determines how the client presents itself to the point. Possible options:

Open- a so-called open network in which all connected devices are authorized immediately
Shared- the authenticity of the connected device must be verified with a key/password
EAP- the authenticity of the connected device must be verified using the EAP protocol by an external server

The openness of the network does not mean that anyone can work with it with impunity. To transmit data in such a network, the encryption algorithm used must match and, accordingly, the encrypted connection must be correctly established. The encryption algorithms are:

None- no encryption, data is transmitted in clear text
WEP- cipher based on the RC4 algorithm with different static or dynamic key lengths (64 or 128 bits)
CKIP- proprietary replacement for Cisco's WEP, an early version of TKIP
TKIP- Improved WEP replacement with additional checks and protection
AES/CCMP- the most advanced algorithm based on AES256 with additional checks and protection

Combination Open Authentication, No Encryption widely used in guest access systems such as providing Internet in a cafe or hotel. To connect, you only need to know the name of the wireless network. Often, such a connection is combined with additional verification on the Captive Portal by redirecting the user HTTP request to an additional page where you can request confirmation (login-password, agreement with the rules, etc.).

Encryption WEP is compromised and cannot be used (even in the case of dynamic keys).

Commonly occurring terms WPA And WPA2 determine, in fact, the encryption algorithm (TKIP or AES). Due to the fact that client adapters have supported WPA2 (AES) for quite some time, there is no point in using TKIP encryption.

Difference between WPA2 Personal And WPA2 Enterprise is where the encryption keys used in the mechanics of the AES algorithm come from. For private (home, small) applications, a static key (password, code word, PSK (Pre-Shared Key)) with a minimum length of 8 characters is used, which is set in the access point settings, and is the same for all clients of a given wireless network. Compromise of such a key (they spilled the beans to a neighbor, an employee was fired, a laptop was stolen) requires an immediate password change for all remaining users, which is only realistic if there are a small number of them. For corporate applications, as the name suggests, a dynamic key is used, individual for each currently running client. This key can be periodically updated during operation without breaking the connection, and an additional component is responsible for its generation - the authorization server, and almost always this is a RADIUS server.

All possible safety parameters are summarized in this plate:

Property	Static WEP	Dynamic WEP	WPA	WPA 2 (Enterprise)
Identification	User, computer, WLAN card	User, computer	User, computer	User, computer
Authorization	Shared key	EAP	EAP or shared key	EAP or shared key
Integrity	32-bit Integrity Check Value (ICV)	32-bit ICV	64-bit Message Integrity Code (MIC)	CRT/CBC-MAC (Counter mode Cipher Block Chaining Auth Code - CCM) Part of AES
Encryption	Static key	Session key	Per-packet key via TKIP	CCMP (AES)
Key distribution	One-time, manual	Pair-wise Master Key (PMK) segment	Derived from PMK	Derived from PMK
Initialization vector	Text, 24 bits	Text, 24 bits	Advanced vector, 65 bit	48-bit packet number (PN)
Algorithm	RC4	RC4	RC4	AES
Key length, bits	64/128	64/128	128	up to 256
Required infrastructure	No	RADIUS	RADIUS	RADIUS

While WPA2 Personal (WPA2 PSK) is clear, an enterprise solution requires further consideration.

WPA2 Enterprise

Here we are dealing with an additional set of different protocols. On the client side, a special software component, the supplicant (usually part of the OS) interacts with the authorization part, the AAA server. This example shows the operation of a unified radio network built on lightweight access points and a controller. In the case of using access points with “brains”, the entire role of an intermediary between clients and server can be taken on by the point itself. In this case, the client supplicant data is transmitted over the radio formed in the 802.1x protocol (EAPOL), and on the controller side it is wrapped in RADIUS packets.

The use of the EAP authorization mechanism in your network leads to the fact that after successful (almost certainly open) client authentication by the access point (together with the controller, if any), the latter asks the client to authorize (confirm its authority) with the infrastructure RADIUS server:

Usage WPA2 Enterprise requires a RADIUS server on your network. At the moment, the most efficient products are the following:

Microsoft Network Policy Server (NPS), former IAS- configured via MMC, free, but you need to buy Windows
Cisco Secure Access Control Server (ACS) 4.2, 5.3- configured via a web interface, sophisticated in functionality, allows you to create distributed and fault-tolerant systems, expensive
FreeRADIUS- free, configured using text configs, not convenient to manage and monitor

In this case, the controller carefully monitors the ongoing exchange of information and waits for successful authorization or refusal of it. If successful, the RADIUS server is able to transfer additional parameters to the access point (for example, which VLAN to place the subscriber in, which IP address to assign, QoS profile, etc.). At the end of the exchange, the RADIUS server allows the client and the access point to generate and exchange encryption keys (individual, valid only for this session):

EAP

The EAP protocol itself is container-based, meaning that the actual authorization mechanism is left to internal protocols. At the moment, the following have received any significant distribution:

EAP-FAST(Flexible Authentication via Secure Tunneling) - developed by Cisco; allows authorization using a login and password transmitted within the TLS tunnel between the supplicant and the RADIUS server
EAP-TLS(Transport Layer Security). Uses a public key infrastructure (PKI) to authorize the client and server (subject and RADIUS server) through certificates issued by a trusted certification authority (CA). Requires issuing and installing client certificates on each wireless device, so is only suitable for a managed corporate environment. The Windows Certificate Server has facilities that allow the client to generate its own certificate if the client is a member of a domain. Blocking a client can easily be done by revoking its certificate (or through accounts).
EAP-TTLS(Tunneled Transport Layer Security) is similar to EAP-TLS, but does not require a client certificate when creating a tunnel. In such a tunnel, similar to a browser SSL connection, additional authorization is performed (using a password or something else).
PEAP-MSCHAPv2(Protected EAP) - similar to EAP-TTLS in terms of the initial establishment of an encrypted TLS tunnel between the client and server, requiring a server certificate. Subsequently, such a tunnel is authorized using the well-known MSCHAPv2 protocol.
PEAP-GTC(Generic Token Card) - similar to the previous one, but requires one-time password cards (and the corresponding infrastructure)

All of these methods (except EAP-FAST) require a server certificate (on the RADIUS server) issued by a certification authority (CA). In this case, the CA certificate itself must be present on the client’s device in the trusted group (which is easy to implement using Group Policy in Windows). Additionally, EAP-TLS requires an individual client certificate. The client's authenticity is verified both by a digital signature and (optionally) by comparing the certificate provided by the client to the RADIUS server with what the server retrieved from the PKI infrastructure (Active Directory).

Support for any of the EAP methods must be provided by a client-side supplicant. The standard built-in Windows XP/Vista/7, iOS, Android provides at least EAP-TLS, and EAP-MSCHAPv2, which makes these methods popular. Intel client adapters for Windows come with the ProSet utility, which expands the available list. Cisco AnyConnect Client does the same.

How reliable is it?

After all, what does it take for an attacker to hack your network?

For Open Authentication, No Encryption - nothing. Connected to the network, and that's it. Since the radio medium is open, the signal travels in different directions, it is not easy to block it. If you have the appropriate client adapters that allow you to listen to the air, network traffic is visible in the same way as if the attacker had connected to the wire, to the hub, to the SPAN port of the switch.
WEP-based encryption requires only IV time and one of many freely available scanning utilities.
For encryption based on TKIP or AES, direct decryption is possible in theory, but in practice there have been no cases of hacking.

Of course, you can try to guess the PSK key or password for one of the EAP methods. There are no known common attacks against these methods. You can try to use social engineering methods, or