What is a Self-Signed Certificate?
Know Is It Safe to Use a Self-Signed Certificate
A self-signed certificate is an alternative to a regular SSL or TLS certificate that does not require third-party validation – instead, the certificate is issued and signed by the public key owner. These types of certificates are most used for purposes such as development and testing. However, they provide a lower level of security than a fully validated certificate, as they can be created without any authentication.
Establishing a secure connection between the client and server is essential when using the internet. A Transport Layer Security or Secure Socket Layer (TLS/SSL) certificate must be implemented to ensure this. These certificates can come in different forms, one of which is a self-signed certificate issued by an individual instead of a Certificate Authority. This type of certificate utilizes both private and public keys, making it easier and more convenient to distribute but also less secure; for this reason, self-signed certificates should not usually be used.
What is a Self-Signed SSL/TLS Certificate?
Self-signed TLS/SSL certificates are not signed by a certificate authority (CA). Instead, the developer of the company running the website signs the certificate. Trust, confidence, and validation are the difference between a CA signing a certificate and a company doing the same.
BEFORE SIGNING THE CERTIFICATE, the CA will run the company or developer through various background and authentication checks. This helps establish the required trust and validation; a website owner or developer must demonstrate their authenticity. Not having the required authentication means the website or application which has a self-signed certificate will have less trust and confidence of the users.
When a CA signs the certificate, they receive this authority from an intermediate and root certificate authority. This, in turn, establishes a chain of trust, which is crucial to building a secure connection between the client and server. The self-signed certificates are generated standalone. These certificates are not linked to any root or intermediate certificate.
As a trusted Certificate Authority does not authenticate these certificates, a security warning will accompany the websites and applications with a self-signed certificate. Web browsers and application stores will detect the type of certificate and raise a red flag. The users trying to access them will see a security warning. This drives away potential customers and users from the website or stops them from downloading the application or software.
Self-signing also links to other digital signing certificates such as S/MIME, code signing, and document signing; the website owner or developer behind a self-signed certificate is unknown and unverified. Because of this, self-signed certificates come with an inherent level of risk, which can include potential man-in-the-middle attacks by fraudsters. As such, web browsers are designed to flag any sites using self-signed certificates as potentially dangerous.
Every other type of SSL certificate has validity. But the self-signed certificates do not have any validity. They can have any validity period because these certificates are not subject to any regulation. Having said that, these certificates do need to be renowned. While the individual can set any length of the validity period, this is not ideal because they can easily forget to renew them due to the longer validity.
What is the Risk of Using Self-Signed Certificates?
Self-signed certificates can be an attractive choice when it comes to securing your website or application due to their low cost. However, before relying solely on self-signed certificates, you should recognize their potential drawbacks. Some of the disadvantages include a lack of trust among website visitors and browsers, and issues with content-filtering applications. It is important to weigh both the positives and negatives of self-signed certificates when deciding about your web security system.
Pros of Self-Signed TLS/SSL Certificates
- Low-Cost or Free: Self-signed TLS/SSL certificates are free to obtain. As these certificates are not supervised and provided by a Certificate Authority and no third party is involved, there is no cost involved in their submission.
- Great for Test Environments: Website owners and developers sometimes have to test-run their websites or applications. Getting a CA-provided TLS/SSL certificate might seem like a money waste here. However, the self-signed certificates provide a good replacement as they function like CA-provided certificates. So, for testing environments, these certificates are great.
- Easy to Customize: Self-signed certificates are flexible in the sense that they can be edited according to the requirements. Because they can be customized, the TLS/SSL certificates can carry more metadata and have greater key sizes.
- Self-Reliant: Self-signed TLS/SSL certificates make a developer or website owner independent. They won’t have to rely on the CAs and other bodies to issue the certificate.
Cons of Self-Signed TLS/SSL Certificates
- Self-Signed certificates are not vetted: One of the biggest concerns with self-signed TLS/SSL certificates is that they are not vetted or undergo a verification process. As a result, anyone can get a self-signed TLS/SSL certificate and run a website or launch an application. Because there is no verification of the entity making the website or software, we cannot guarantee whether it is legitimate or not.
- A Serious Security Risk: Assuming a user gains access to a website with a self-signed TLS/SSL certificate, they usually browse the website. Even so, they can share private and sensitive information like bank details, credit card numbers, social security numbers, etc. This is a big risk for the person sharing these details because we don’t have any idea about the website owner and publisher. Second, because the connection is not secure, any other party can access private and confidential information.
- Non-Revocable: To everyone’s surprise, a certificate authority cannot revoke a self-signed TLS/SSL certificate. This means that even if a CA wants to revoke the certificate and render it redundant, they cannot do so after issuing the certificate.
- Lack of Control: In addition to the CA, the security teams do not have complete control over the self-signed TLS/SSL certificates. They lack the required visibility and control over these certificates. Due to this, even when there is a security risk, the security teams cannot implement the required resolution.
Utilizing a self-signed certificate is not recommended to weigh the advantages and disadvantages. The website owner and publisher are risking their reputation as well as exposing their users’ information by using these certificates. Therefore, the possible risks associated with the use of these certificates outweigh their benefits.
Self-signed TLS/SSL certificates come with many drawbacks that outnumber their benefits. It is impossible to tell who owns the website, where the software is installed, if and where the private key is stored, or if it has been compromised. Furthermore, these certificates are not revocable, which lacks security control. Considering this, it is advisable to avoid getting self-signed SSL/TLS certificates.
Final Thoughts on What is a Self-Signed Certificate
In conclusion, self-signed certificates can be convenient due to their customization capabilities and ease of administration. However, they do not provide good validation of the identity of the owner or publisher. For this reason, CA-signed certificates should be chosen instead to protect the website and its reputation better.