A certificate signing request (CSR), also known as a certification request, is an application for a digital certificate from a certificate authority (CA).
It’s the first step in a digital certificate management program that enables organizations to strengthen their security posture and the visibility of their certificate inventory. In light of rapidly shrinking certificate lifecycles that will be as short as 47 days by 2029, this process is critically important—as demands for certificates increase, the costs of application downtime skyrocket.
To reduce the risk of service interruptions, organizations managing short-lived certificates must monitor certificate expiration and schedule CSR generation well in advance. 7–10 days before the certificate’s expiration is ideal. This approach allows time for validation, approval, and deployment, helping maintain business continuity and avoiding last-minute scrambling.
A CSR includes:
- The public key from the key pair that will be used to encrypt the certificate
- Identifying information, including organization and domain details such as Common Name (CN), Organization Name (ON), Organizational Unit (OU), and location
- Organizational contact information
RSA, DSA, ECC, and other cryptographic algorithms generate public and private keys for CSRs. Each request must define the key type and its length, measured in bits. This length determines encryption strength. RSA typically uses 2048-bit keys, although stronger keys, such as 3072-bit, 4096-bit, and even 7168-bit, are also common.
The CSR is stored in the PEM format using Base-64. PEM (Privacy-Enhanced Mail) is the most common format for storing and transmitting digital certificates and keys. The binary data contained in a PEM file is not specified beyond its Base-64 encoding and the special formatting with BEGIN and END wrapping. Common labels such as CERTIFICATE, CERTIFICATE REQUEST, PRIVATE KEY, and more are used to distinguish between different cryptographic data. The PEM format is versatile and widely supported, helping generate CSRs in an efficient, secure way.
What Makes a Good CSR
Accuracy and completeness of a CSR are paramount because they often lead to a better, more timely TLS/SSL certificate.
This is easy enough when you only have a few to create. What happens when you need to process hundreds or perhaps thousands of CSRs, and do so repeatedly every 47 days? With the rapidly scaling volume and pace of CSR generation, automated systems are no longer just a “nice to have.” They save time and greatly improve accuracy because much of the information is repeatable, like the organization’s name and contact information.
Creation errors can lead to a cascade of delays, threatening downtime and throwing off the whole certificate lifecycle, which can have long-lasting implications for systems dependent on short-lived certificates.
A robust certificate signing request process that accounts for the need to generate CSRs at scale while still centering on security and compliance is crucial for enterprises.
Well-documented automated processes boost efficiency and improve your security posture.
Security and Trust
Following optimal security requirements for certificate applications in line with the organization’s security standards to generate CSRs is an important part of digital certificate management.
One piece of the CSR puzzle to consider is the encryption key length.
2048-bit private keys are standard. Is a longer key, such as a 4096-bit one, better? Longer keys indeed provide stronger encryption; however, they may also impact website performance and speed of certificate validation—key exchanges are slower with larger keys. Each organization has to carefully consider its needs and obligations to find a balance between performance and security requirements.
Once the key pair of an appropriate length is created, the CSR file will securely and reliably link the public and private keys to prevent cryptographic flaws.
Ensuring the CSR is correct and complete helps certificate authorities verify both the domain and the organization with a multi-step validation process, granting a higher verification status if needed, and enabling visible trust indicators like HTTPS on web properties.
Compliance and Legal Requirements
The CA/B Forum, an industry group, sets standards for CSR creation and provides guidelines across the certificate lifecycle. The uniform rules accelerate certificate request processing and assist with diagnosing problems with valid certificates in the wild. Equally important, encryption and certificate standards protect all parties using the digital certificates, including enterprises themselves.
Good documentation is a hallmark of a well-managed process. Ensure your PKI solution includes tools to document your processes, audit support, and adherence to industry standards. This is particularly important for organizations serving highly-regulated industries such as healthcare and financial services. Your documentation is an important diagnostic tool that lowers your rate of certificate rejection and mitigates a myriad of liability risks. A well-documented process provides a paper trail to help an organization survive internal and external audits.
Operational Efficiency and Cost Savings
A lack of a defined process increases costs due to haphazard manual tasks and places a heavy burden on IT and security staff. With certificate lifespans shortening, what used to be an annual task to generate CSRs for renewals is soon going to turn into a frantic scramble that repeats every 47 days.
Fewer errors return certificate requests faster and with less hassle. Certificate rejections and misconfigurations are less likely, minimizing the need to redo a request. This reduces the risk of certificate expiry and outages.
3 Tips to Request Certificates the Right Way
While your organization’s security needs are unique and your exact CSR request process will differ from another organization’s, the following tips and best practices guidelines will ensure its smooth functioning regardless of your industry.
1. Use private keys
Private keys are the backbone of secure CSRs and digital certificates. Create strong private keys to help defend against brute-force attacks, Harvest Now Decrypt Later attacks, and malicious decryption attempts. Private keys should have a minimum length of 2048 bits or greater, according to the latest security recommendations from the U.S. National Institute of Standards and Technology.
Despite keys being private, attackers are still effective at using social engineering to compromise your systems. Keep private keys secure—never share them with anyone. Consider a hardware security module (HSM) or a dedicated key management system to limit access to private keys only to essential roles in your organization.
2. Select a reputable certificate authority
Prioritize trust and support when choosing a certificate authority (CA). Your CA should be able to handle multiple certificate types to adapt to your security requirements. This includes offering Standard SSL certificates in addition to Extended Validation (EV) certificates that include more rigorous checks and provide higher assurance of authenticity and legitimacy. This level of assurance is often critical for large enterprises.
3. Review, verify, and submit
Prior to submitting the file to a CA, double-check all of the information included in it, ensure the file is correctly formatted, and verify domain ownership.
Once it’s time to submit the file, ensure the channel you’re using to transmit it is secure. Email can have security vulnerabilities, so if you must send the file via email, consider encrypting it and using a secure out-of-band method to share the encryption key. If possible, use secure APIs for submitting the file and require user authentication for API access.
Conclusion: Enhancing Digital Trust
A well-defined and documented certificate signing request process plays an important role in digital trust. Many enterprises still rely on spreadsheet tracking and manual certificate issuance and renewal requests, despite clear evidence that the level of PKI efficiency and precision required at an enterprise level is very hard to achieve without automation.
Manual certificate management processes will not withstand the impending industry shift to the 47-day certificate validity. Issuance delays, misconfigurations, and failed validations are inevitable without tools that simplify and automate certificate management. Organizations must invest in robust processes today to generate CSRs without error, minimize downtime, and avoid potential service disruptions that impact their reputation and may result in a loss of trust.
Keyfactor’s solutions, including Keyfactor EJBCA and Keyfactor Command, can transform your manual processes into proactive, automated certificate lifecycle management solutions.
