How does DNSSEC improve the security of my DNS infrastructure?

The Domain Name System (DNS) is the backbone of the Internet, enabling the translation of easy-to-remember domain names, such as www.eunetic.com, into numerical IP addresses.  This translation is crucial as computers and networks use IP addresses to communicate with each other. DNS therefore acts as a kind of "telephone book" of the Internet. However, DNS also poses security risks. Traditional DNS protocols do not necessarily confirm the authenticity of the DNS responses received, which can lead to potential points of attack for malicious manipulation. DNSSEC was developed to close this security gap.

What is DNSSEC?

DNSSEC (Domain Name System Security Extensions) is a security extension for the Domain Name System and DNSSEC plays a crucial role in ensuring the authenticity and integrity of DNS data. It refers to cryptographic signatures that are added to DNS records to protect data transmitted over IP networks. DNSSEC is a kind of digital signature that is added to every DNS response and verifies its origin. This creates a level of trust that goes beyond conventional DNS mechanisms.

The security enhancement has arisen because no security measures were included in the protocols when the DNS system was created. This makes it possible for attackers to falsify data records and redirect Internet users to fake, fraudulent websites. The use of DNSSEC makes it possible to verify the DNS data received.

DNS infrastructure security is necessary because traditional DNS protocols are vulnerable to various types of attacks. Without adequate security measures, DNS queries are vulnerable to man-in-the-middle attacks, spoofing and cache poisoning. These attacks can lead to false or spoofed DNS responses, which in turn can lead to fraudulent activity, data loss and identity theft. DNSSEC was developed to counteract these vulnerabilities and create a trustworthy DNS infrastructure.

Important terms: RRSIG, DNSKEY, DS, NSEC

To understand how DNSSEC works, it is necessary to look at some key terms that are added depending on the situation:

• RRSIG (Resource Record Signature)

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  RRSIG is a cryptographic signature that is added to a DNS response to ensure its authenticity.
• DNSKEY (DNS Key)

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  DNSKEY is the public key used to verify the RRSIG signatures. This key is provided by the DNS servers and forms the basis for the chain of trust.
• DS (Delegation Signer)

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  DS contains the hash of a DNSKEY record and is used to identify and chain DNSSEC-signed zones.
• NSEC (Next Secure)

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  NSEC is a resource record that indicates that no other resource records exist between two domain names. This is used to check the integrity of the namespace.

How does DNSSEC work?

A. Signing DNS data

The main task of DNSSEC is to sign DNS data to ensure its authenticity and integrity. This is done through the use of cryptographic techniques. Here are the key steps:

1. Private and public key

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   Each DNS server that implements DNSSEC has a private key and a corresponding public key. The private key is kept secret and is used to sign DNS data, while the public key is used to verify these signatures.
2. Digital signatures

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   When a DNS server generates a DNS response, it signs it using its private key. This digital signature is called an RRSIG (Resource Record Signature) and is transmitted together with the original DNS response.

B. Verification of DNS data

After DNS data has been signed, it must be verified to ensure that it is authentic and unchanged. This verification process includes the following steps:

1. Authentication chain (Chain of Trust)

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   The authentication chain, also known as the "chain of trust", is crucial for the trustworthiness of DNSSEC. It begins with the public key of the root certification authority (root DNS server), which represents the highest level of the DNS hierarchy. This public key is used to verify the authenticity of the key of the top-level domain (TLD) server. Authentication continues as each subsequent DNS server authenticates the previous one with its public key until the key of the target domain server is reached.
2. DNSSEC validation

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   DNSSEC validation takes place on the client or resolver side. When the resolver receives a DNS response, it checks the digital signature (RRSIG) with the corresponding public key. By checking the signature and the authentication chain, the resolver ensures that the DNS data has not been manipulated and originates from an authorized DNS server.

The functionality of DNSSEC is therefore based on the signing of the data by servers with their private keys and the subsequent verification by the user side using the public keys and authentication chain. This process ensures the secure transmission of DNS information and protects against various types of attacks that could jeopardize the integrity of the DNS infrastructure.

WHY IS DNSSEC IMPORTANT?

Implementing DNS Security Extensions (DNSSEC) is critical to improving the security of the DNS infrastructure and minimizing potential points of attack. Here are some of the main reasons why DNSSEC plays a key role in today's networked world:

• Pharming

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  DNSSEC protects against pharming attacks, where attackers attempt to redirect users to fake websites in order to intercept personal information. By verifying the authenticity of DNS data, DNSSEC successfully prevents legitimate domain names from being redirected to fraudulent IP addresses.
• Cache Poisoning

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  Another threat that DNSSEC protects against is cache poisoning. In this attack, the DNS cache of a server is manipulated with false information. DNSSEC ensures that the DNS responses received are signed and have not been manipulated by an attacker, which significantly reduces the effectiveness of cache poisoning attacks.
• Protection against spoofing attacks

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  DNS spoofing refers to the provision of fake DNS responses to redirect users to malicious websites. DNSSEC prevents such attacks by verifying the authenticity of DNS data. If DNS responses do not originate from an authorized server or have been manipulated, this is detected by DNSSEC and the forged information is blocked.
• Ensuring data integrity

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  DNSSEC not only guarantees the authenticity of DNS data, but also ensures that the transmitted information remains unchanged during the transmission process. The digital signature used by DNSSEC protects against data tampering and ensures that the DNS data received is exactly the same as that signed by the authorized server.

Overall, DNSSEC contributes significantly to the security of the DNS infrastructure by mitigating various attack vectors. By preventing DNS tampering, protecting against spoofing attacks and ensuring data integrity, DNSSEC creates a trusted environment for the transmission of DNS information, which is crucial for the security of Internet users.

AUTHENTICITY AND INTEGRITY OF DNS DATA THROUGH DNSSEC

The basis of DNSSEC lies in ensuring the authenticity and integrity of DNS data. It authenticates the origin of DNS data by providing a clear mechanism for verifying the identity of the domain. This is done by establishing a chain of trust, starting with the public key of the root DNS server and progressing to the public keys of the top-level domain (TLD) servers and finally to the specific domain servers. Each key in this chain is used to verify the authenticity of the next key in the hierarchy and in the end the authenticity of the entire domain is ensured.

The digital signature RRSIG, which is generated by DNSSEC, plays a decisive role in the authentication of DNS data. The public key of the sending server is used to verify the signature. If the signature is correct and the associated public key is authenticated, it can be assumed that the DNS data originates from a legitimate and authorized server.

DNSSEC can be used to prevent man-in-the-middle attacks, in which an attacker attempts to manipulate communication between two parties. As DNSSEC verifies the authenticity of DNS data, an attacker cannot smuggle forged DNS information into the communication path unnoticed. The verification of the signature and the authentication chain prevent an attacker from successfully acting between the communication partners. Furthermore, DNSSEC effectively protects against forged DNS responses by ensuring that the data received is authentic and unaltered. The digital signature guarantees that the DNS responses actually originate from an authorized server and have not been manipulated during transmission. This protection mechanism is crucial to ensure the trustworthiness of DNS data and to ensure that Internet users are not redirected to fake or malicious websites.

In summary, DNSSEC ensures the authenticity and integrity of DNS data by combining domain authentication, signature verification and effective protection against man-in-the-middle attacks and spoofed DNS responses. This makes a significant contribution to strengthening the security and reliability of the entire DNS infrastructure.

HOW CAN I ACTIVATE DNSSEC FOR MY DOMAIN?

If you use our Anycast network, you can activate DNSSEC within the zone of your domain. Proceed as follows:

WHAT ARE THE CHALLENGES AND PROBLEMS OF USING DNSSEC?

Although the implementation of DNS Security Extensions (DNSSEC) brings significant security benefits, it is not without its challenges. On the one hand, the introduction of DNSSEC can be a challenge due to its complexity. This mainly concerns the correct configuration of key pairs, the rotation of keys and the management of signatures. Domain owners must deal with the various aspects of cryptography and ensure that the keys are generated and stored securely. The complexity can lead to errors if not enough expertise is available, which in turn could compromise the effectiveness of DNSSEC.

On the other hand, the implementation of DNSSEC can also have an impact on the performance of the DNS. The additional cryptographic operations, especially the verification of digital signatures, can increase response times. This is particularly relevant for large DNS infrastructures with many queries. The additional DNS query responses from DNSSEC can also increase the risk and impact of DDoS attacks, as the technology requires additional fields and cryptographic information to verify the legitimacy of records. With our powerful Anycast DNS, however, this point can be neglected.