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Exploring E2EE: Real-world Examples of End-to-End Encryption

by Robert Dougherty updated June 30, 2025 Secure File Sharing

Reading Time: 11 minutes

With the meteoric rise of cyber threats and data breaches, end-to-end encryption (E2EE) has emerged as a vital tool for safeguarding sensitive information. In this blog post, we will explore E2EE, its purpose, importance, how it works, and real-world applications. We will also discuss the benefits and limitations of E2EE, industries that utilize it, and best practices for businesses to implement it.

Table of Contents

What Is End-to-End Encryption?

End-to-end encryption is a process that encrypts data at the source and decrypts it only at the destination. It ensures that the data is secure at every stage of transmission, from the sender to the recipient. E2EE differs from other encryption methods, such as transport layer security (TLS), which only encrypts data in transit.

In E2EE, the encryption process takes place on the user’s device, which generates a unique encryption key to encrypt the data. The recipient’s device uses a matching decryption key to decrypt the data. This ensures that only the sender and recipient have access to the information, even if it is intercepted during transmission.

How End-to-End Encryption Differs From Other Encryption Practices

End-to-End Encryption (E2EE): This is the most secure form of digital communication. Encryption happens on the sender’s device and the data can only be decrypted by the intended recipient’s device. The service provider in the middle cannot access the plaintext data. The keys required to decrypt the information are held exclusively by the end users. Typical use cases: Secure messaging apps like Signal and private file sharing platforms.
In-Transit Encryption (e.g., TLS/SSL): This is the encryption you see when your browser shows a padlock icon (HTTPS). It encrypts data as it travels between your device and a server. However, the server decrypts the data upon arrival. This means the service provider has access to your unencrypted information. Typical use cases: Secure web browsing, standard email services, and connecting to most online applications.
At-Rest Encryption: This method protects data that is stored on a server, hard drive, or database. It prevents data from being read if the physical hardware is stolen. However, it does not protect the data from anyone who has legitimate access to the server or application, as the system can decrypt the data to use it. Typical use cases: Protecting files stored in cloud services and securing database contents.

These differences are critical for security and compliance. While in-transit and at-rest encryption are essential security layers, they create a “man in the middle” vulnerability where the service provider can be compelled to turn over user data or become a target for man in the middle (MITM) attacks and subsequent data breaches.

End-to-end encryption eliminates this central point of failure. For regulations like GDPR and HIPAA, which mandate strict data privacy, using E2EE provides a much stronger compliance posture by ensuring that sensitive content is never accessible to unauthorized parties, including the platform provider itself.

How Strong Is End-to-End Encryption?

The strength of end-to-end encryption depends on the encryption algorithms used and the key management process. Common encryption algorithms used in E2EE include the Advanced Encryption Standard (AES), RSA, and the Signal Protocol. These algorithms are considered secure and have been widely adopted for their robustness against attacks.

Encryption key management is also crucial in ensuring the security of E2EE. Effective key management involves generating, distributing, storing, and periodically refreshing encryption keys. Poor key management can lead to vulnerabilities in the encryption process, which can compromise the overall security of the communication channel.

What Does End-to-End Encryption Protect Against?

End-to-end encryption provides robust protection against several specific and pervasive digital threats by ensuring that data remains confidential and integral from its origin to its destination. It effectively creates a secure private tunnel across public or untrusted networks.

Protection From Eavesdropping and Interception

The primary threat that end-to-end encryption mitigates is eavesdropping. When data travels across the internet, it passes through numerous routers and servers controlled by various third parties, including internet service providers (ISPs). Without E2EE, any of these intermediaries could potentially intercept and read the data. With E2EE, the data is scrambled into unreadable ciphertext, rendering it useless to anyone who intercepts it. For example, in the healthcare industry, E2EE is vital for telemedicine communications to ensure patient-doctor confidentiality and comply with HIPAA, preventing unauthorized parties from listening to consultations or accessing shared medical records containing personally identifiable and protected health information (PII/PHI).

Protection From Service Provider Snooping

Many online services encrypt data in transit to their servers, but then decrypt it for processing or storage. This means the service provider itself—whether a cloud storage company, email provider, or social media platform—can access the data.

E2EE eliminates this possibility. The provider can see that data is being transmitted but has no way to decipher its content. In the financial sector, this is a critical security measure. When a wealth manager shares sensitive portfolio information with a client using an E2EE platform, they have a guarantee that even the platform’s employees cannot view that confidential financial data, protecting client privacy and adhering to stringent financial regulations.

Protection From Data Modification

Modern E2EE implementations often use authenticated encryption, which not only ensures confidentiality but also guarantees data integrity and authenticity.

This means that the system can detect if data has been tampered with or modified in transit. An attacker cannot secretly alter the content of an end-to-end encrypted message without the recipient’s device detecting the change and flagging the message as invalid. This prevents sophisticated attacks where an adversary might try to change payment amounts in a financial transaction or alter a legal document as it is being sent.

How Safe Is End-to-End Encryption?

The cryptographic algorithms underlying modern end-to-end encryption, such as AES 256 encryption, are considered practically unbreakable by today’s computing standards. A brute-force attack would take billions of years to succeed. Therefore, the safety of E2EE does not typically depend on the strength of the encryption itself, but rather on the security of the systems implementing it. The primary risks are not in breaking the encryption, but in bypassing it.

The most significant vulnerability lies at the “ends” of the end-to-end chain: the user devices. If an attacker can compromise a sender’s or recipient’s device with malware, spyware, or a keylogger, they can access data before it’s encrypted or after it’s decrypted. This is known as a compromised endpoint attack.

Similarly, if a user’s private key is stolen, either through a phishing attack or direct device compromise, an attacker can impersonate that user and decrypt their messages. While E2EE protects data in transit, it cannot protect data on an insecure device.

To maintain the safety of end-to-end encryption, it is crucial to follow these best practices:

Secure Your Endpoints: Use strong passwords, biometric authentication, and reputable antivirus/anti-malware software on all devices.
Keep Software Updated: Regularly update your operating system and applications to patch security vulnerabilities that could be exploited.
Verify Contacts: Use features within secure apps to verify the identity of your contacts (e.g., by scanning a QR code or comparing safety numbers) to prevent man in the middle (MITM) attacks.
Be Wary of Phishing: Never share your private keys and be suspicious of any messages asking you to compromise your security settings.

In summary, while end-to-end encryption is a powerful tool for privacy, it is not a complete security solution on its own. Its effectiveness depends on a foundation of good overall digital hygiene.

Real-world Examples of End-to-End Encryption

In this section, we will explore real-world examples of E2EE in popular messaging and email services, including WhatsApp, Signal, and ProtonMail.

WhatsApp’s End-to-End Encryption

WhatsApp is a popular messaging app that uses end-to-end encryption to protect user messages, voice calls, and video calls. E2EE on WhatsApp relies on the Signal Protocol, an open-source encryption method developed by Open Whisper Systems. When a message is sent through WhatsApp, it is encrypted on the sender’s device using a unique encryption key. The encrypted message is then transmitted to the recipient’s device, where it is decrypted using the corresponding key.

The advantages of WhatsApp’s E2EE include protecting user privacy from hackers, governments, and even WhatsApp itself. However, WhatsApp has faced some controversy surrounding its encryption implementation, primarily due to concerns about metadata collection and the app’s ownership by Facebook, which has a history of data privacy issues.

Signal’s End-to-End Encryption: Features and Benefits for Secure Messaging

Signal is an open-source messaging app that prioritizes privacy and security. Like WhatsApp, Signal uses the Signal Protocol for end-to-end encryption, ensuring that only the sender and receiver of a message can read its contents. Signal’s encryption applies to all forms of communication within the app, including text messages, voice calls, video calls, and group chats.

One of the main advantages of Signal’s E2EE is its commitment to user privacy. The app collects minimal data on users and has a clear privacy policy that outlines its data handling practices. Additionally, Signal has been endorsed by privacy advocates, cybersecurity experts, and even high-profile figures like Edward Snowden.

ProtonMail’s End-to-End Encryption: Protecting Emails From Hacking and Surveillance

ProtonMail is a secure email service that uses end-to-end encryption to protect user data. When an email is sent through ProtonMail, it is encrypted on the sender’s device using the recipient’s public key. The encrypted email is then stored on ProtonMail’s servers, where it can only be decrypted using the recipient’s private key.

ProtonMail’s end-to-end encryption offers numerous advantages, including protection from surveillance, hacking, and other security threats. The service also includes additional security features, such as two-factor authentication and zero-knowledge password storage, to further protect user data.

Industries That Implement End-to-End Encryption

End-to-end encryption is used in various industries to protect sensitive data and maintain user privacy. Some examples include:

Healthcare: E2EE is often used in telemedicine and electronic health record systems to protect patient data from unauthorized access.
Finance: Banks and financial institutions use E2EE to secure online transactions and communications between customers and employees.
Communication: Messaging apps, email services, and videoconferencing tools use E2EE to ensure secure communication between users.
Education: Online learning platforms and student data management systems use E2EE to protect student and faculty data.
E-commerce: E2EE is used to secure payment information and customer data during online transactions.

Exploring E2EE Beyond Messaging Apps: How Cloud Storage and VPNs Use End-to-End Encryption

E2EE is not limited to messaging apps and is also used in cloud storage and VPNs.

End-to-End Encryption in Cloud Storage: Real-world Examples

E2EE can be utilized in cloud storage services. These services allow users to encrypt files on their device before uploading them to the cloud. This ensures that only the user has access to the encryption keys and the uploaded data.

However, the limitations of E2EE in cloud storage include the fact that it may result in slower file access and sharing. Additionally, if a user forgets their encryption key, it may not be possible to recover the data.

Virtual Private Networks and End-to-End Encryption: A Closer Look at How VPNs Secure Data

VPNs use E2EE to secure internet traffic and protect user data from interception. VPNs such as NordVPN and ExpressVPN use E2EE to encrypt traffic between the user’s device and the VPN server.

E2EE in VPNs can enhance security by preventing unauthorized access to data and protecting user privacy. However, implementing E2EE in VPNs can also result in slower internet speeds.

How to Implement End-to-End Encryption

With end-to-end encryption, only the intended recipients can access the data, making it difficult for hackers or other third parties to intercept or steal the information. Here are the steps to implement end-to-end encryption:

1. Choose an Appropriate Encryption Protocol

There are several encryption protocols available, including AES, RSA (Rivest-Shamir-Adleman), and PGP (Pretty Good Privacy). Choose the encryption protocol that best suits your needs.

2. Generate Public and Private Keys

Each device involved in the communication needs to generate a unique public and private key. The public key is shared with other devices, while the private key is kept secret.

3. Exchange Public Keys

The devices involved in the communication need to exchange their public keys, allowing them to encrypt messages that only the intended recipient can decrypt.

4. Encrypt Data

Once the public keys have been exchanged, data can be encrypted with the recipient’s public key.

5. Decrypt Data

To read the encrypted data, the recipient needs to decrypt the data using their private key.

6. Use Secure Communication Channels

To ensure the security of the communication, use secure channels such as HTTPS, SSL/TLS, or a virtual private network.

7. Implement Security Best Practices

End-to-end encryption is just one layer of security. To ensure maximum security, implement other best practices such as two-factor authentication, strong passwords, and regular software updates.

By following these steps, you can implement end-to-end encryption and secure your communication against unauthorized access.

Best Practices for End-to-End Encryption

End-to-end encryption is a critical component of online security and privacy. It ensures that communication between two parties is confidential and cannot be intercepted by third parties. However, deploying effective end-to-end encryption requires careful consideration of various factors, including encryption algorithms, key management, user authentication, and software updates. In this blog post, we outline the best practices for implementing end-to-end encryption to ensure that your data remains secure and private.

1. Use a Trusted Encryption Algorithm

Use a recognized encryption algorithm such as AES for data encryption. This ensures that your encryption method is secure and trustworthy.

2. Generate Unique Encryption Keys

It is important to generate a unique encryption key for every user and every conversation. This ensures that even if one key is compromised, the others remain secure.

3. Store Keys Securely

The encryption keys should be stored securely and separately from the encrypted data. This ensures that even if an attacker gains access to the encrypted data, they cannot decipher it without the key.

4. Use Perfect Forward Secrecy

Perfect forward secrecy (PFS) ensures that even if one key is compromised, the attacker cannot use it to decrypt previous conversations. Instead, a new key is generated for each communication session.

5. Verify User Identity

End-to-end encryption relies on trust between users. To ensure that each user is who they claim to be, use secure identity verification methods such as two-factor authentication or digital certificates.

6. Make Sure the Encryption is User-friendly

The user interface should clearly show that end-to-end encryption is on and functioning properly. This assures users that their conversations are secure and private.

7. Test the Encryption Regularly

Regular testing of the encryption system ensures that it is working as expected. This includes testing for key generation, data encryption, and decryption.

8. Keep Software Up to Date

Keep your encryption software up to date with the latest security patches and updates. This ensures that any security vulnerabilities are fixed quickly.

9. Use a Reputable Provider

When seeking an end-to-end encryption provider, choose a reputable company with a good track record of security and privacy.

10. Educate Users About Encryption

End-to-end encryption relies on user trust and understanding. Educate users about the importance of encryption, how it works, and how to use it correctly.

E2EE and Data Privacy Laws

Compliance with data privacy laws is essential for businesses that handle sensitive information. Data privacy laws govern the collection, storage, processing, and sharing of personal data. These laws aim to protect individuals’ sensitive information from unauthorized access, misuse, and abuse. Examples of data privacy laws include the European Union’s General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA).

The use of E2EE and compliance with data privacy laws go hand in hand. Businesses that handle sensitive data must comply with data privacy laws, which often require them to implement security measures to protect users’ personal information. End-to-end encryption is one of the most effective ways to secure data and ensure compliance with data privacy regulations. By encrypting data at every step of its journey, E2EE ensures that only the intended recipient can access it and that no one else can intercept or access it.

However, there has been some debate about the use of E2EE, with some authorities arguing that it can be used to conceal criminal activity. In some cases, governments have attempted to force tech companies to provide backdoor access to encrypted data. Such requests, if granted, could undermine the security and privacy of individuals using messaging apps. Therefore, it is crucial to strike a balance between privacy and security concerns and comply with data privacy laws to safeguard personal data.

Kiteworks Protects Sensitive Content at Rest and in Transit With End-to-End Encryption Over a Private Data Network

The Kiteworks Private Data Network (PDN) offers enterprise-grade security and compliance features that allow businesses to communicate with clients and customers, while ensuring the privacy of sensitive information. The platform’s end-to-end encryption capability is built into Kiteworks secure email, Kiteworks secure file sharing, secure MFT, Kiteworks SFTP, secure virtual data rooms, and other channels, allowing organizations to share information quickly and securely.

One of Kiteworks’ key advantages is the ability to deploy encrypted files up to 16 TB, providing businesses with the capability to share and store large files securely. The platform also features a comprehensive security and compliance stack, including AES-256 encryption for data at rest, TLS 1.3 for data in transit, granular access controls, authentication, and comprehensive audit logs and audit reporting. This allows organizations to quickly and easily adhere to data privacy standards, enabling HIPAA compliance, PCI compliance, CMMC 2.0 compliance, GDPR compliance, FedRAMP compliance, NIST 800-171 compliance, IRAP compliance, and many others.

Kiteworks integrates with major SIEM solutions, including IBM QRadar, ArcSight, FireEye Helix, and LogRhythm. This enables organizations to monitor and respond to security events in real time, reducing the risk of cyberattacks and data breaches.

Kiteworks also provides visibility and management tools, including a CISO Dashboard that gives an overview of information, user access, compliance, and usage. This enables business leaders to make informed decisions and maintain compliance with industry regulations. Additionally, Kiteworks offers a single-tenant cloud environment, ensuring no shared resources or potential for cross-cloud breaches or attacks.

To get more information on end-to-end encryption and the Kiteworks Private Data Network, schedule a custom demo today.