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What Is End-to-End Encryption & How Does It Work?

by Bob Ertl updated January 23, 2024 Secure Email

Reading Time: 9 minutes

End-to-end encryption is a necessary security measure that keeps proprietary and sensitive information secure. But how does it actually work?

What is end-to-end encryption? End-to-end encryption is a way to secure data while it’s being sent from one party to another. The data is encrypted while it’s being transferred. Thus, if someone were to intercept the data, it would be unreadable.

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What Is End-to-End Encryption and How Does It Work?

“Encryption” is the practice of obfuscating information so that it remains unreadable to unauthorized third parties. This obfuscation works by utilizing mathematical functions to transform clear data into a code that can only be decoded through a specific reverse process, often using a “key” to facilitate decryption as a form of authentication.

To guarantee that encrypted data remains safe, encryption methods rely on complex transformations that make it virtually impossible to reverse those transformations without the proper access.

There is not a one-size-fits-all encryption approach for all data, however. Rather, encryption is applied in several different ways, based on specific use conditions of that data. These include the encryption of data in the following contexts:

Encryption At Rest

Encryption at rest is a security measure that uses encryption to protect data while it is stored or not in use. It works by encrypting the data with a cryptographic key or hashing algorithms.

Data that is encrypted at rest is less vulnerable to data breaches, since attackers would need to decrypt the data in order to use it. It is often used in conjunction with other security measures, such as authentication, access control, and data loss prevention.

Encryption In Transit

Encryption in transit is a type of cryptographic protection that safeguards data as it travels between two systems or networks over a public or shared network, such as the internet. When data is encrypted in transit, it is protected from eavesdropping, manipulation, and other malicious activities. Encrypted data is less vulnerable to espionage and other malicious activities, which makes it safer for use in public or shared networks.

Encryption In Use

Data “in use” can mean that the data is visible on a terminal or stored in local memory at a workstation. While in-use encryption is not as common as the other versions (although it is becoming more so), encryption approaches for in-use data include hardware-encrypted RAM.

Protecting and keeping data private when at rest and in transit are the two most common encryption challenges. In the case of the former, strong encryption, perimeter security, and access management are important starting points. But recent research also finds that additional security and compliance protocols are needed in the form of a Private Content Network (PCN) that involves these and other governance tracking and controls (more below).

Data is a critical business enabler, both between internal constituents and with third parties. Accordingly, service providers and businesses must implement encryption to allow multiple users to share data, usually through public or vulnerable private systems, while protecting that data from common threats like man-in-the-middle attacks or eavesdropping attacks.

End-to-end encryption—which needs to be part of every organization’s third-party risk management (TPRM) strategy—addresses both issues by encrypting the data before it is transmitted, such that the data doesn’t rely on a server or in-transit encryption scheme to protect it. Both the sender and receiver use a specific encryption method to encrypt and decrypt the information, and the information remains obfuscated both while at rest in a server and during transit.

How Is End-to-End Encryption Different From In-transitor At-rest Encryption?

The main difference between end-to-end encryption and other approaches is that it is a complete solution from sender to receiver. In contrast, at-rest and in-transit methods only encrypt in a specific context.

Consider a typical email service. While we often don’t pay attention to the technical details of regular email, most providers provide both at-rest and in-transit encryption:

Email servers often are protected with AES-128 or AES-256 encryption.
Email transmissions will almost invariably use some version of transport layer security (TLS), the modern version of SSL tunnels. Additionally, users connecting to these email providers via web services must often use HTTPS, the secure form of HTTP.

The problem with the above setup is that it doesn’t protect information sufficiently for most secure applications. There’s no way to fully guarantee that email moves to a secure environment as it goes through every single mail server with which it interacts on its way to its final destination.

To address this, E2E encrypts the data independent of the technologies implemented for transmission or in the server. This involves encrypting the data itself at the point of transmission and sending the encrypted data through public channels (regardless of any other encryption protocols like TLS), delivering an obfuscated message that only the end-user can decrypt.

Note the difference: With E2E encryption, the encryption and decryption of information are limited to the users, not the owner of the server or infrastructure. Encryption occurs at the level of the device, not the server.

More specifically, end-to-end encryption uses asymmetric encryption keys:

Symmetric encryption: In symmetric systems, encryption and decryption occur with the same key. One system encrypts the message using a specific key, while receiving systems decrypt that data using an identical key distributed to them.
Asymmetric encryption: Also known as public key encryption, asymmetric systems use a collection of public and private keys to support public encryption. Under these schemas, a user has a public key (shared with the public at large or any colleagues in an organization) and a private key (kept secret from everyone else).
Anyone who wants to send an encrypted message to that user will use their public key, and the receiver must decrypt that message with their private key. Messages encrypted with a public key can only be decrypted with the corresponding private key.

Most encryption methods are symmetric. AES, for example, utilizes identical keys that, while strong, also require significant security and maintenance. Many E2E solutions, however, use some form of asymmetric encryption.

Why Does Encryption Matter for Data Security?

Encryption is a process that helps to protect data from unauthorized access, providing an added layer of security for data stored or transmitted over a network. It has become an essential security measure for organizations of all sizes and is used to protect data from unauthorized access, identity theft, malicious attacks, and other forms of cybercrime.

Encryption helps to ensure that the data cannot be accessed or modified by anyone other than the sender or recipient. It does this by transforming the data into a “secret code” or cipher, which requires a key to decrypt it. Without the key, the encrypted data is unintelligible and cannot be read by anyone with access to the data. This helps to ensure that only authorized personnel can access the data, and that any modifications made to the data are limited to authorized users.

Encryption is also important for compliance with various laws and regulations, such as HIPAA and GDPR. These regulations often require organizations to take steps to protect sensitive information, and encryption.

How Can Encryption Help Your Organization?

Encryption helps an organization protect the sensitive data of its customers, employees, and partners by rendering it unreadable to anyone without the appropriate decryption key. It prevents malicious actors from accessing sensitive data, thereby protecting an organization from data loss, identity theft, and financial fraud.

Organizations can use encryption to protect various types of data, including confidential customer information, financial documents, and private communications. By encrypting highly sensitive data, organizations can prevent unauthorized access and protect their reputation. Additionally, encrypted data cannot be easily modified or corrupted, ensuring their integrity and authenticity.

Encryption also helps organizations ensure compliance with data privacy regulations. Many regulations, such as GDPR, require organizations to protect personal data with encryption and other security measures. By encrypting sensitive data, organizations can demonstrate they are taking steps to ensure compliance.

What Are the Benefits and Challenges of End-to-End Encryption?

Obviously, there are significant benefits to end-to-end encryption, or there wouldn’t be ongoing conversation about it. Expanded protection and user-centered security are part of the approach organizations use to address end-to-end encryption.

Advantages of End-to-End Encryption

Robust data protection: E2E encryption is, as the name suggests, protection from start to finish. The transmitted information is obfuscated at the point that it is sent and isn’t decrypted until the end recipient does so. Additionally, asymmetric systems allow for more accessible encryption over public transmission channels.
Privacy: E2E encryption provides higher levels of privacy than its counterparts. Because the information is encrypted via key, anyone, including service providers or routing nodes, cannot see that information unless they have that public key.
Stronger defense against admin attacks: Because public and private keys are in the hands of users, they don’t require management by administrators. In turn, system administrators aren’t points of failure because they cannot give up this key information, and hacks against admin accounts don’t necessarily compromise user encryption.
Compliance: Because many regulatory compliance frameworks require complete encryption protection for data at all points of transmission and storage, typical at-rest or in-transit solutions alone aren’t sufficient, meaning they can’t be used to share protected information. However, properly configured E2E can, in many cases, satisfy compliance requirements like NIST-regulated contexts (FedRAMP, NIST 800-53), HIPAA, or CMMC.

While these are huge benefits for any organization that values security, there are also some significant challenges:

Implementation: End-to-end encryption isn’t a shared technology. Unlike AES or TLS (where providers often leverage standardization to promote interoperability), E2E systems run into the adoption issue. It’s difficult to put into practice a public key system that can satisfy all users and providers, which makes it almost impossible to implement E2E for public communications reliably.
Likewise, public key systems often require more resources to create and compute encryption keys, unlike their symmetric counterparts. Large systems must devote significant computational power to support E2E.
Social engineering: So long as public keys remain private, these are secure. Hackers can, with the proper knowledge, trick users into exposing their keys. This problem can be mitigated with a key management system, but you lose some of the benefits of E2E by centralizing access.

PCI DSS and Data Encryption

Encryption helps in PCI DSS compliance by ensuring that all data is encrypted when stored or transmitted. This prevents malicious actors from gaining access to credit card information, customer records, and other sensitive data. PCI DSS requires that organizations use strong encryption algorithms (e.g., AES) with key lengths of at least 128 bits, and that they use a unique key to encrypt each data element.

Encryption also helps with PCI DSS compliance by preventing data breaches. If an organization’s systems are breached and the data is encrypted, the attackers will not be able to access the data. This is because they do not have the key to decrypt the data. Encryption also helps to protect data from being intercepted while in transit, preventing it from being stolen or modified.

Get the Benefits of End-to-End Encryption With Kiteworks

In most cases, major enterprises in heavily regulated industries have struggled with encryption and privacy issues, even as they look for new ways to share information freely and securely with their customers. Solutions like private portals, secure links, and other measures have served as a stopgap solution in many cases but aren’t as ideal as direct communication with the public.

With a Kiteworks-enabled Private Content Network, businesses gain the security and power of an end-to-end encryption scheme built into enterprise-grade secure email, file sharing, managed file sharing (MFT), web forms, and application programming interfaces (APIs). Furthermore, end-to-end encryption capabilities in the Kiteworks platform include an email protection gateway powered by totemo, an acquisition that allows us to deliver end-to-end email encryption from any email server.

One key advantage of a Kiteworks-enabled private content network is that we customers with Kiteworks-hosted deployments, where encrypted files up to 16 TB (maximum file size on Linux systems) can be sent or shared.

With Kiteworks, you can count on the following features:

Security and compliance: Kiteworks utilizes AES-256 encryption for data at rest and TLS 1.2+ for data in transit. The platform’s hardened virtual appliance, granular controls, authentication, other security stack integrations, and comprehensive logging and audit reporting enable organizations to easily and quickly demonstrate compliance with security standards. The Kiteworks platform has out-of-the-box compliance reporting for industry and government regulations and standards, such as the Health Insurance Portability and Accountability Act (HIPAA), Payment Card Industry Data Security Standard (PCI DSS), SOC 2, and General Data Protection Regulation (GDPR).
In addition, Kiteworks touts certification and compliance with various standards that include, but are not limited to, FedRAMP, FIPS (Federal Information Processing Standards), and FISMA (Federal Information Security Management Act). Likewise, Kiteworks is assessed to IRAP (Information Security Registered Assessors Program) PROTECTED level controls. Additionally, based on a recent assessment, Kiteworks achieves compliance with nearly 89% of Cybersecurity Maturity Model Certification (CMMC) Level 2 practices.
Audit logging: With the Kiteworks platform’s immutable audit logs, organizations can trust that attacks are detected sooner and maintain the correct chain of evidence to perform forensics.
Since the system merges and standardizes entries from all the components, Kiteworks’ unified syslog and alerts save security operations center teams crucial time while helping compliance teams to prepare for audits.
SIEM integration: Kiteworks supports integration with major security information and event management (SIEM) solutions, including IBM QRadar, ArcSight, FireEye Helix, LogRhythm, and others. It also has the Splunk Forwarder and includes a Splunk App.
Visibility and management: The CISO Dashboard in Kiteworks gives organizations an overview of their information: where it is, who is accessing it, how it is being used, and if data being sent, shared, or transferred complies with regulations and standards. The CISO Dashboard enables business leaders to make informed decisions while providing a detailed view of compliance.
Single-tenant cloud environment: File sharing, automated file transfers, file storage, and user access occur on a dedicated Kiteworks instance, deployed on-premises, on an organization’s Infrastructure-as-a-Service (IaaS) resources, or hosted as a private single-tenant instance by Kiteworks in the cloud by the Kiteworks Cloud server. This means no shared runtime, shared databases or repositories, shared resources, or potential for cross-cloud breaches or attacks.

To get more information on secure email, end-to-end encryption, and Kiteworks’ private content network, read more about Kiteworks secure email.

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