The Best Ways of Securing Server-to-Server Communications (API to API)

In the blockbuster sequel Pirates of the Caribbean: Dead Man’s Chest, Jack Sparrow and company embark on a convoluted quest to find both a key and the chest it opens. Compasses, chests, keys, and jars of dirt change hands throughout the film, but the right combination of keys, chests, and hands doesn’t culminate until the next instalment. 

As far as security goes, the buried treasure may be good enough for most pirates, but is it good enough for your users?

Server-to-server communication is the backbone of many internet systems, but advancements in security bring along with them advancements in security circumvention. These new challenges in securing server-to-server communication require software companies and developers to be familiar with the latest and best tools for ensuring their API security.

What Are API Keys?

API keys provide a great solution when APIs need to communicate. Since API keys are static and easily generated and revoked, they are an effective and straightforward way to secure your communication.

But what are API keys? An API key is a unique identifier used to authenticate a user, developer, or program in an Application Programming Interface. API keys can be assigned specific access (such as read or write permissions) and when generated with The Auth API, they can be implemented in flexible and versatile ways.

API keys are short and static, meaning they’re efficient to generate and can continue to be used until their access is revoked—one of the many functionalities that The Auth API provides.

Alternatives to Server-to-Server Communication

There are advantages and disadvantages to every structure, but the alternatives to server-to-server communication have significant downsides to keep in mind. Here are some alternatives to server-to-server communication, as well as the reasons they may not be the best fit for your API:

1. User-to-Server Communication

User-to-server (or client-server) communication is efficient and requires minimal maintenance due to centralized data. While those benefits are worthwhile for many applications, there are serious pitfalls to be aware of.

The biggest downside of user-to-server communication is that it breaks the security paradigm. Building increasingly secure firewalls is a short-term solution to an escalating long-term problem as more and more critical data is spread between server and client locations.

2. Security Through Obscurity

Security Through Obscurity (STO) relies on hiding weaknesses from bad actors by withholding critical information about a system’s loopholes and vulnerabilities. However, by restricting information about a system to only a few key stakeholders, the weak points in the castle walls are hard for hackers to identify.

While STO is a good practice in limited applications, its greatest flaw is that once pandora’s box opens, it’s hard to close. Security through obscurity is a limited strategy to make it harder for bad actors to get in, but STO alone isn’t enough to keep your data secure once they have access.

Challenges of API Key Implementation

While API keys are immensely useful, they aren’t without their pitfalls. Here are some of the challenges to keep in mind when implementing API keys:

• Don’t Over-Provision User Roles. It may seem easier to give broad access upfront and restrict access down the line, but often, the restriction never happens. This over-provisioning of access can cause serious IT risks that far outweigh the productivity benefits of broad access. 68% of organizations don’t pay attention to elevated IT access before adding new permissions, leaving them unnecessarily vulnerable and putting them at risk for cyber attacks due to unmonitored privileges.
• Back up API Keys with SSL/HTTPS. An API Key alone is generally not considered secure. Because your client has access to the key, that leaves it vulnerable to Man-In-The-Middle (MITM) attacks and other forms of cybersecurity threats. Due to that vulnerability, API keys must be backed up with SSL/HTTPS. Embedding API keys directly in code is not recommended—it leaves you and your clients vulnerable to having keys accidentally exposed or stolen. Rather, use HTTPS referrers or encrypt the links between servers through SSL authentication.
• Use Access Control for Authentication and Authorization. Access control is the practice of restricting authentication and authorization. Authentication is like the bouncer at the door—it determines who has the right identification to be allowed in. On the other hand, authorization limits what users are allowed to do once they’re in the door. Limiting who has access to your API and what changes they’re allowed to make, limits the damage a bad actor can cause.
• Use Best Practices for Password Protection. Set up guidelines for what constitutes a strong password to protect your users from brute force attacks. Don’t be fooled into thinking modern users are tech-savvy enough to create strong passwords of their own volition: in 2021, the password “123456” was used over 100 million times and takes less than one second to crack. Encourage your users to use passwords at least 12 characters long using alphanumeric and special characters. Limiting the number of password attempts and encrypting password data are also effective ways to preempt brute force attacks.
• Log All API Key Usage. The perseverance of API keys is both a strength and a weakness. Strong because the keys don’t expire, but weak because once stolen, they can be difficult to track down and revoke unless you keep appropriate logs of what servers use API keys. Having a clear audit trail is essential to identifying and fixing breaches if and when they occur, and an API platform like The Auth API is the easiest way to log your API key usage.
• Keep The Implementation Simple. Avoid over-building. API keys should be simple enough for any dev to implement well. That’s where The Auth API comes into the picture. They take the guesswork out of API key implementation, so you don’t have to reinvent the wheel and your devs can breathe easy. The Auth API gives you the tools to implement API keys into your server-to-server communications painlessly and efficiently with robust controls and versatile features.

API Key Best Practices

Now that you know why API keys are the best way to secure server-to-server communications and you’re aware of what challenges to be cautious of, here are some time-tested best practices to set you on the path toward success. Of course, your software needs are as diverse and individual as you are, but these best practices take some of the guesswork out of tailoring your communication security to your specific needs.

• User Roles Should Be Limited. Defining the right user roles is an important part of keeping your data secure. Limiting the number of users with read and write access to your software is vitally important, and it’s always best to be conservative with your permissions and loosen them as needed, rather than to be generous with permissions and try to get the cat back in the bag down the road. Limiting user rules is one safeguard against privilege escalation, a type of cyber attack where a user exploits a flaw in your system to give themselves more permissions than intended initially. Keeping your access well-controlled limits your exposure to risks such as privilege escalation.
• Keep a Record of All Servers Who Use an API Key. This goes hand in hand with keeping logs of API key usage. Keeping a record of every server that tries to use an API key allows you to identify anomalous patterns. One of the benefits of API keys is that it allows you to keep track of the companies with API key access, and what individuals at those companies control the keys.
• Identify Optimization Areas. Having a strong idea of how your organization is structured and what your data needs are is the key to using API keys effectively. The best practice is to use only one API key for each system needing data access. By identifying your systems and data needs, you can identify the best way to segment your API key usage to eliminate overlap and redundancy.
• Assign Roles to Key Holders. API key holders aren’t necessarily individual users. Create stratified permission categories by identifying who needs what permissions and to what systems. Remember that the key concept is to eliminate overlap as much as possible, but portioning out the appropriate roles to key holders requires a total view of what categories key holders fall into.
• Generate Strong API Keys. The key to API security is to generate strong API keys. API keys include alphanumeric and special characters, and a strong API key should be randomly generated, unique, and non-guessable. For example, The Auth API uses a secure random generator designed for cryptography, and they recommend switching the hex encoding to Base64.
• Store API Keys Securely. Fort Knox’s locks are no good if the keys fall into the wrong hands. Once API keys are generated securely, they also must be stored securely. Your keys need to access, but to avoid keeping all your eggs in one basket, they should be stored by generating a hash value. When users send an API key request, their API key is hashed and compared against the stored hash value for an additional level of security. This ensures that even if your infrastructure is compromised, a bad actor can’t gain access to your users’ API keys.

Advantages of Securing Server-to-Server Communication

Protecting your most vital information is no small task, and you may be wondering if all this fuss about API keys is worth your time.

Your security is your greatest asset: without it, your most precious data can be stolen, tampered with, or abused. Keeping communication between servers secure is a top priority not only for your safety but also for your users’ safety. API calls now make up 83% of all web traffic, meaning your API-to-API security is more important today than it ever has been. There are many advantages to maintaining secure server-to-server communication:

1. Anomaly Detection

Having secure server-to-server communication lets you to keep a close eye on your API key usage. By leveraging the tools at your disposal to analyze trends and keep track of the programs, users, and companies that use your API, you can ensure that your greatest asset is in only the best hands. 

2. Identity Detection

With an expanding repertoire of security circumvention tools at their disposal, bad actors are adept at gaining access to your infrastructure. API keys allow you to identify which users are compromised so that you can revoke permissions and make the appropriate changes. Technology is still a fundamentally human discipline, and the humans you work with are still vulnerable to deception and carelessness. Almost all cyber-attacks involve social engineering and using keys to maintain API security ameliorates the human error factor in keeping your data secure. Using API keys to maintain secure server-to-server communication allows you to stay in the driver’s seat of your security.

3. Maintain Security, Maintain Trust

Stewardship of your data and your client’s data is a key to building trust. A shocking 41% of companies have over 1,000 files of sensitive data such as credit card numbers and health records that are left completely unprotected. With the unprecedented rise of cybercrime post-Covid, developers need to be more aware now than ever that their security is a top priority.

Putting API Keys into Practice with The Auth API

It’s one thing to understand the technology and another to know how to act on it. API security may sound ethereal, but when an average data breach costs over $8 million, the impact of secure server-to-server communication suddenly becomes very tangible.

Now that you know all about API keys, best practices, and why server-to-server security is so important, what are the tangible steps you can take to implement these ideas with The Auth API?

• Identify Your Needs. No two organizations are exactly alike. Identify what users and permission levels make the best use of your resources.
• Choose The Plan That Fits Your Organization. The Auth API offers plans for single-access API platforms all the way up to large teams. Once you’ve identified your API security needs, select the best plan for your unique organization.
• Generate and Store API Keys. Use The Auth API’s cryptographic key generation to create and store secure API keys for your users.
• Record and Manage Your Users. With The Auth API, there’s no need to spend your days pouring over records: their third-party-audited platform detects bad actors and sends you an email every month detailing the regular usage of your API keys, and alerting you immediately when anomalies are detected.
• Generate, Refresh, and Destroy Keys. There is any number of reasons your keys may become compromised. Whether by a malicious MITM attack, simple negligence, or staff turnover, there is any number of reasons you might want to generate new keys, refresh old ones, or delete users entirely. The Auth API makes this process painless by enabling you to perform these tasks with the flip of a switch.
• Protect Yourself from Malicious Attacks. From social engineering to permission escalation to man-in-the-middle attacks, you already know how using API keys can help keep your API secure, but did you know that The Auth API also monitors for and prevents Distributed Denial of Service (DDoS) attacks too? By allowing you to set up granular rate limiting, you can prevent costly and disruptive attacks from succeeding.

All of this starts with The Auth API. Take the guesswork out of your API security by using their state-of-the-art platform to manage your API keys and take charge of your most precious asset: your security. Take control today by starting a free trial or booking a demonstration to see how their API platform can revolutionize your API security.