The Best Way to Encrypt Contracts: A Guide for Legal & Business Professionals

The American Bar Association has famously compared sending unencrypted confidential documents via email to sending a postcard through the mail. Anyone who handles it along the way—from the mail carrier to the sorting facility—can flip it over and read it.

When that “postcard” contains a Non-Disclosure Agreement (NDA), a merger strategy, or a settlement draft, the stakes are infinitely higher. Contracts are the crown jewels of business data. They contain Social Security numbers, bank wiring instructions, and intellectual property that defines your company’s future.

Yet, despite the risks, 36% of law firms reported experiencing a security incident in 2024 (ABA Tech Report).

Many professionals believe they are safe because they “password protect” a PDF or use a secure cloud link. Unfortunately, these standard methods often provide a false sense of security. The best way to encrypt contracts is through Client-Side Encryption (CSE)—a method where you lock the file on your own device before it ever touches the cloud, an email server, or a transfer tool.

This guide explores why relying on cloud storage isn’t enough, the hidden risks of “leaky contracts,” and how to use offline encryption to secure your deals without disrupting your workflow.

Why “Standard” Protections Fail

Most professionals rely on two main methods to secure contracts: the built-in password features of their document editor, or the security promises of their cloud storage provider. Both have significant vulnerabilities that modern attackers exploit daily.

The PDF Password Fallacy

It is a common misconception that adding a password to a Microsoft Word document or an Adobe PDF encrypts the file. In many cases, these tools apply “access controls” rather than robust encryption.

Older versions of these tools (and some current settings) use weak encryption standards like RC4, which can be cracked in minutes using free software available online. Even with newer standards, the implementation often leaves metadata exposed. If a hacker intercepts a password-protected PDF, they can often use “brute force” tools to bypass the lock without ever knowing the password.

If you are relying on a simple password to protect a multimillion-dollar agreement, you are essentially locking a bank vault with a zip tie.

The Cloud Storage Trap (Google Drive/Dropbox)

Cloud providers like Google Drive, Dropbox, and OneDrive boast about “Encryption at Rest.” This sounds secure, but there is a catch: they hold the keys.

When you upload a contract to Google Drive, it is encrypted on their servers. However, Google possesses the decryption key. This means that if Google is subpoenaed, they can decrypt and hand over your files. More worryingly, if a hacker compromises your account credentials (or compromises the provider itself), the encryption offers you no protection because the system automatically decrypts the file for anyone logged in.

The cost of these oversights is staggering. Data breaches now cost companies an average of $4.88 million—a record high according to IBM’s 2024 report. For a small law firm or independent contractor, a fraction of that cost could be fatal.

The Ransomware Evolution: Double Extortion

The threat landscape has shifted. A few years ago, ransomware simply locked your files. Today, attackers use “Double Extortion.”

In these attacks, hackers don’t just encrypt your data; they exfiltrate (steal) it first. They then threaten to publish your sensitive contracts online if you don’t pay the ransom.

According to the 2024 Embroker/ABA Tech Report, there has been an 11% increase in ransomware attacks specifically targeting law firms. Cybersecurity analysts note that for legal and business professionals, “the threat isn’t just losing access to your contracts, it’s having them published publicly.”

If your contracts are encrypted locally before the breach occurs, the hackers steal nothing but useless, scrambled data.

Real-World Scenarios: When Contracts Leak

The abstract concept of “data security” often obscures the devastating reality of a leak. Here is what happens when contracts are intercepted in the real world.

Scenario A: Real Estate Wire Fraud (The “Michael” Story)

Michael, a real estate attorney in Atlanta, was managing a $600,000 commercial property closing. Weeks before the closing date, hackers compromised his email account via a phishing link. They didn’t strike immediately. Instead, they monitored the unencrypted contract drafts bouncing back and forth between Michael and the buyer.

They learned the closing date, the bank details, and the tone of Michael’s writing. On the morning of the closing, the hackers sent an email from a “spoofed” address (mimicking Michael’s email by one letter) containing “updated” wiring instructions.

Because the buyer had been reading unencrypted emails with similar context for weeks, they didn’t hesitate. They wired $600,000 to the fraudulent account. The money was unrecoverable, and Michael faced a malpractice lawsuit for failing to secure client communications.

The Lesson: Unencrypted emails allow hackers to learn the context needed to execute successful scams.

Scenario B: The IP Theft (The “David” Story)

David, a freelance software engineer, met a potential client at a coffee shop to finalize a project. He connected to the shop’s public Wi-Fi and emailed his Statement of Work (SOW) and technical specs.

He didn’t realize a “Man-in-the-Middle” attacker was intercepting traffic on that open network. The attacker captured the unencrypted DOCX file. Although the deal with the client eventually fell through, David was shocked to see a competitor launch a clone of his proposed app months later. The competitor had used the detailed specifications from the intercepted SOW to fast-track development.

The Lesson: Public Wi-Fi combined with unencrypted files leaves your Intellectual Property wide open to theft.

Scenario C: The Reputation Hit (The “Sarah” Story)

Sarah, a talent agent, was finalizing a massive endorsement deal for a professional athlete. She saved the draft contract—containing sensitive salary bonuses and exclusivity clauses—to her laptop’s desktop.

While she was at a dinner meeting, her car was broken into, and her laptop was stolen. The thief wasn’t just looking for hardware; they sold the data on the device to a tabloid. The leak of the athlete’s financial demands caused the sponsor to pull out of the deal due to a breach of confidentiality. The client lost $4 million, and Sarah’s reputation in the industry was ruined.

The Lesson: Physical theft happens. If the file isn’t encrypted at rest on your device, the data is gone the moment the device is taken.

Comparing the 3 Ways to Encrypt Contracts

Not all encryption methods are created equal. When choosing how to protect your documents, you generally have three options.

Option 1: Enterprise Cloud Suites (e.g., Kiteworks, Citrix)

These are large-scale platforms designed for major corporations.

• Pros: Highly integrated, offers audit trails.
• Cons: Extremely expensive and complex to set up. They often require the recipient to create an account and log into a specialized portal just to download one file. This adds friction to deals and frustrates clients.

Option 2: Native Application Tools (Adobe/Word)

These are the built-in password features discussed earlier.

• Pros: Convenient and free.
• Cons: Weak security (often vulnerable to brute-force attacks). They do not offer true “at rest” encryption for the file itself, merely an access gate that is easily bypassed by determined attackers.

Option 3: Local-First / Client-Side Encryption (The Recommended Method)

This approach involves encrypting the file on your device using a dedicated tool like sekura.app before you send it.

• Definition: You turn the contract into an unreadable, locked file (e.g., .skrp) on your computer.
• Why it’s the “Best Way”: It creates a decoupled workflow. Once the file is encrypted locally with AES-256 encryption (the military and banking gold standard), it doesn’t matter how you send it. You can attach it to an email, drop it in Slack, put it on a USB drive, or upload it to Dropbox. Even if those channels are hacked, the file remains secure.

Step-by-Step: How to Encrypt Contracts with Sekura

Using local encryption sounds technical, but modern tools have made it as easy as dragging and dropping a file. Here is how to secure your contracts using a decoupled workflow.

Step 1: Preparation

Finalize your contract in your preferred editor (Word, PDF, etc.). Save it to your computer. You do not need to add a password inside Word or Acrobat—we are going to apply much stronger protection.

Step 2: Local Encryption

Open sekura.app on your desktop. Since Sekura is a local-first application, this process happens entirely offline. Your file is not being uploaded to a server; it is being processed right on your machine.

Drag and drop your contract into the app window.

Step 3: Key Generation

You will be prompted to set a password or passphrase.

• Choose a strong passphrase (e.g., “Blue-Coffee-Mug-2024!”).
• Sekura uses this passphrase to generate the encryption key.
• Note: Because this is zero-knowledge encryption, there is no “Forgot Password” button. You are the only person who knows this key.

Step 4: The Transfer (The Decoupled Method)

Once you click “Encrypt,” you will have a secured file (e.g., contract.pdf.skrp).

• Send the File: Attach this encrypted file to your standard email or upload it to your cloud folder.
• Send the Key: This is the most crucial step. Do not email the password in the same thread as the file. Send the password via a different channel, such as Signal, SMS, or a phone call.

Step 5: Decryption

Your client receives the file. They open Sekura (or use the decryption tool), enter the password you sent via text, and the file unlocks instantly. They can now read the contract knowing it was never exposed during transit.

Best Practices for Contract Security

Technology is only half the battle. To truly protect your agreements, you need to combine encryption software with strong behavioral habits.

Out-of-Band Authentication

We mentioned this in Step 4, but it bears repeating. Never send the lock and the key together. If a hacker has access to your email to steal the file, they also have access to read the password you just emailed.

By sending the password via SMS or a secure messaging app (like Signal), a hacker would need to compromise both your email and your phone simultaneously to access the data.

Key Management as a Feature

“If you lose the key, you lose the data.”

This scares some users, but it is actually a security feature. If a software provider can reset your password, it means they have a way to access your key. If they can access it, so can a government agency or a hacker. True privacy requires that you—and only you—control the keys. Use a password manager to keep track of your encryption passphrases.

Compliance Check

For many professionals, encryption isn’t just a good idea—it’s the law.

• GDPR: Requires appropriate technical measures to protect personal data.
• HIPAA: Demands encryption for any documents containing health information.
• Legal Ethics: Lawyers have a duty to take reasonable efforts to protect client confidences.

Poor security has a direct financial impact beyond fines. The World Commerce & Contracting (WorldCC) reports that companies lose 9.2% of contract value annually due to poor contract management and security practices.

Internal Link Opportunity: For more on managing your keys securely, read our guide on [How to Create and Store Strong Passwords].

FAQ: Common Questions About Contract Encryption

Is password protecting a PDF enough? No. Standard PDF password protection is often based on older security protocols that can be cracked in minutes with widely available software. For sensitive legal documents, you need AES-256 encryption, which is virtually unbreakable.

Can I use Google Drive if I have 2FA? Two-factor authentication (2FA) protects access to your account, but it does not protect the privacy of your files from Google itself. Google retains the decryption keys for everything on Drive. If you want true privacy, you must encrypt the file locally before uploading it to the cloud.

How do I send a contract securely to a non-tech-savvy client? Local encryption is often easier for clients than enterprise portals. With a portal, clients usually have to create an account, verify their email, and navigate a complex dashboard. With a tool like Sekura, they simply receive a file and type in a password. It mimics the familiar “password protected zip file” workflow but with military-grade security.

Is it legal to encrypt contracts for government work? Yes. In fact, for many government contracts (especially those involving the DoD or CMMC requirements), encryption is mandatory. You are often required to control the encryption keys yourself, which cloud-based storage does not allow.

Conclusion

Securing your contracts is no longer optional. With the rise of wire fraud, double-extortion ransomware, and intellectual property theft, the “postcard” method of emailing raw files is a liability you cannot afford.

Technology alone isn’t the savior; the workflow is. By adopting a local-first encryption strategy, you decouple your security from your transport method. You gain the freedom to send files via email, Slack, or cloud storage without fear, knowing that the data itself is locked tight.

As security technologist Bruce Schneier famously said, “Encryption must be the default, not an afterthought.”

Don’t wait until a breach compromises your next deal. Take control of your data today. Download sekura.app to start encrypting your contracts with offline, military-grade security.