Email encryption is encryption of email messages to protect the content from being read by entities other than the intended recipients. Email encryption may also include authentication.
Email is prone to disclosure of information. Most emails are currently transmitted in the clear (not encrypted) form. By means of some available tools, persons other than the designated recipients can read the email contents.
Email encryption can rely on public-key cryptography, in which users can each publish a public key that others can use to encrypt messages to them, while keeping secret a private key they can use to decrypt such messages or to digitally encrypt and sign messages they send.
With the original design of email protocol, the communication between email servers was plain text, which posed a huge security risk. Over the years, various mechanisms have been proposed to encrypt the communication between email servers. Encryption may occur at the transport level (aka “hop by hop”) or end-to-end. Transport layer encryption is often easier to set up and use; end-to-end encryption provides stronger defenses, but can be more difficult to set up and use.
One of the most commonly used email encryption extensions is STARTTLS . It is a TLS (SSL) layer over the plaintext communication, allowing email servers to upgrade their plaintext communication to encrypted communication. Assuming that the email servers on both the sender and the recipient side support encrypted communication, an eavesdropper snooping on the communication between the mail servers cannot use a sniffer to see the email contents. Similar STARTTLS extensions exist for the communication between an email client and the email server (see IMAP4 and POP3, as stated by RFC 2595). STARTTLS may be used regardless of whether the email’s contents are encrypted using another protocol.
The encrypted message is revealed to, and can be altered by, intermediate email relays. In other words, the encryption takes place between individual SMTP relays, not between the sender and the recipient. This has both good and bad consequences. A key positive trait of transport layer encryption is that users do not need to do or change anything; the encryption automatically occurs when they send email. In addition, since receiving organizations can decrypt the email without cooperation of the end user, receiving organizations can run virus scanners and spam filters before delivering the email to the recipient. However, it also means that the receiving organization and anyone who breaks into that organization’s email system (unless further steps are taken) can easily read or modify the email. If the receiving organization is considered a threat, then end-to-end encryption is necessary.
The Electronic Frontier Foundation encourages the use of STARTTLS, and has launched the ‘STARTTLS Everywhere’ initiative to “make it simple and easy for everyone to help ensure their communications (over email) arent vulnerable to mass surveillance.” Support for STARTTLS has become quite common; Google reports that on GMail 90% of incoming email and 90% of outgoing email was encrypted using STARTTLS by 2018-07-24.
Mandatory certificate verification is historically not viable for Internet mail delivery without additional information, because many certificates are not verifiable and few want email delivery to fail in that case. As a result, most email that is delivered over TLS uses only opportunistic encryption. DANE is a proposed standard that makes an incremental transition to verified encryption for Internet mail delivery possible. The STARTTLS Everywhere project uses an alternative approach: they support a preload list of email servers that have promised to support STARTTLS, which can help detect and prevent downgrade attacks.
In end-to-end encryption, the data is encrypted and decrypted only at the end points. In other words, an email sent with end-to-end encryption would be encrypted at the source, unreadable to service providers like Gmail in transit, and then decrypted at its endpoint. Crucially, the email would only be decrypted for the end user on their computer and would remain in encrypted, unreadable form to an email service like Gmail, which wouldn’t have the keys available to decrypt it. Some email services integrate end-to-end encryption automatically.
Notable protocols for end-to-end email encryption include:
OpenPGP is a data encryption standard that allows end-users to encrypt the email contents. There are various software and email-client plugins that allow users to encrypt the message using the recipient’s public key before sending it. At its core, OpenPGP uses a Public Key Cryptography scheme where each email address is associated with a public/private key pair.
OpenPGP provides a way for the end users to encrypt the email without any support from the server and be sure that only the intended recipient can read it. However, there are usability issues with OpenPGP it requires users to set up public/private key pairs and make the public keys available widely. Also, it protects only the content of the email, and not metadata an untrusted party can still observe who sent an email to whom. A general downside of end to end encryption schemeswhere the server does not have decryption keysis that it makes server side search almost impossible, thus impacting usability.
The Signed and Encrypted Email Over The Internet demonstration has shown that organizations can collaborate effectively using secure email. Previous barriers to adoption were overcome, including the use of a PKI bridge to provide a scalable public key infrastructure (PKI) and the use of network security guards checking encrypted content passing in and out of corporate network boundaries to avoid encryption being used to hide malware introduction and information leakage.
Transport layer encryption using STARTTLS must be set up by the receiving organization. This is typically straightforward; a valid certificate must be obtained and STARTTLS must be enabled on the receiving organization’s email server. To prevent downgrade attacks organizations can send their domain to the ‘STARTTLS Policy List'
Most full-featured email clients provide native support for S/MIME secure email (digital signing and message encryption using certificates). Other encryption options include PGP and GNU Privacy Guard (GnuPG). Free and commercial software (desktop application, webmail and add-ons) are available as well.
While PGP can protect messages, it can also be hard to use in the correct way. Researchers at Carnegie Mellon University published a paper in 1999 showing that most people couldn’t figure out how to sign and encrypt messages using the current version of PGP. Eight years later, another group of Carnegie Mellon researchers published a follow-up paper saying that, although a newer version of PGP made it easy to decrypt messages, most people still struggled with encrypting and signing messages, finding and verifying other people’s public encryption keys, and sharing their own keys.
Because encryption can be difficult for users, security and compliance managers at companies and government agencies automate the process for employees and executives by using encryption appliances and services that automate encryption. Instead of relying on voluntary co-operation, automated encryption, based on defined policies, takes the decision and the process out of the users’ hands. Emails are routed through a gateway appliance that has been configured to ensure compliance with regulatory and security policies. Emails that require it are automatically encrypted and sent.
If the recipient works at an organization that uses the same encryption gateway appliance, emails are automatically decrypted, making the process transparent to the user. Recipients who are not behind an encryption gateway then need to take an extra step, either procuring the public key, or logging into an online portal to retrieve the message.
Continue reading here:
Email encryption – Wikipedia
- encryption - How secure is AES-256? - Cryptography Stack ... - June 2nd, 2019
- The World's Email Encryption Software Relies on One Guy, Who ... - May 5th, 2019
- Encryption breakthrough could keep prying eyes away from your ... - May 5th, 2019
- What Is Data Encryption? Definition, Best Practices & More ... - May 1st, 2019
- IronClad Encryption Partners with Data443 Risk Mitigation ... - April 30th, 2019
- What Is Encryption? An Overview of Modern Encryption ... - April 30th, 2019
- Symmetric vs. Asymmetric Encryption What are differences? - April 29th, 2019
- Difference Between Hashing and Encryption - ssl2buy.com - April 29th, 2019
- What is Advanced Encryption Standard (AES)? - Definition ... - April 29th, 2019
- How to Encrypt Your Wireless Network - Lifewire - April 29th, 2019
- After Paris, Encryption Will Be a Key Issue in the 2016 ... - April 22nd, 2019
- What is Encryption, and Why Are People Afraid of It? - April 8th, 2019
- Data encryption | cryptology | Britannica.com - April 8th, 2019
- How to Enable Full-Disk Encryption on Windows 10 - April 1st, 2019
- After Paris, Encryption Will Be a Key Issue in the 2016 Race - March 27th, 2019
- Does Encryption Really Help ISIS? Heres What You Need to ... - March 27th, 2019
- AES and RSA Encryption Explained - March 27th, 2019
- Encryption: What it is and why its important - Norton - March 23rd, 2019
- Email encryption in transit - Gmail Help - March 21st, 2019
- Authenticated encryption - Wikipedia - March 19th, 2019
- Email Encryption Options for MDaemon Email Server - March 14th, 2019
- How to Encrypt Files on Windows - Tutorial - Toms Guide - March 6th, 2019
- Encryption, Key Management - bank information security - March 5th, 2019
- Which Types of Encryption are Most Secure? - February 7th, 2019
- JSON Object Signing and Encryption (JOSE) - February 4th, 2019
- What Is Encryption, and How Does It Work? - January 26th, 2019
- The Pitfalls of Facebook Merging Messenger, Instagram, and ... - January 26th, 2019
- Encryption: Avoiding the Pitfalls That Can Lead to Breaches - January 14th, 2019
- Encryption | Information Technology Services - December 31st, 2018
- Encryption - Investopedia - December 16th, 2018
- How to Protect Data at Rest with Amazon EC2 Instance Store ... - December 9th, 2018
- Next Generation Encryption - blogs.cisco.com - December 4th, 2018
- 3 Different Data Encryption Methods - DataShield blog - November 22nd, 2018
- Security and encryption | Documentation | Turtl - November 18th, 2018
- Encryption | General Data Protection Regulation (GDPR) - November 16th, 2018
- Using Encryption and Authentication Correctly (for PHP ... - November 13th, 2018
- Encryption | SANS Security Awareness - November 9th, 2018
- Types of Encryption | Office of Information Technology - November 5th, 2018
- Use Your own Encryption Keys with S3s Server-Side ... - October 29th, 2018
- What is Tokenization vs Encryption - Benefits & Uses Cases ... - October 12th, 2018
- Device Encryption | it.ucsf.edu - October 12th, 2018
- 5 Common Encryption Algorithms and the Unbreakables of the Future - September 15th, 2018
- Top 5 best encryption software tools of 2018 | TechRadar - August 26th, 2018
- New EBS Encryption for Additional Data Protection | AWS ... - August 22nd, 2018
- Best Encryption Software 2018 - Encrypt Files on Windows PCs - August 20th, 2018
- Download BestCrypt Volume Encryption 3.78.05 / 4.01.09 Beta - July 26th, 2018
- End-to-end encryption - Wikipedia - July 24th, 2018
- Download Symantec Encryption Desktop 10.4.0 Build 1100 - July 15th, 2018
- HTTPS - Wikipedia - July 10th, 2018
- AES encryption - June 20th, 2018
- Encrypt email messages - Outlook - June 20th, 2018
- Download Sophos Free Encryption 188.8.131.52 - softpedia.com - June 19th, 2018
- Does Skype use encryption? | Skype Support - June 16th, 2018
- Encryption- Computer & Information Security - Information ... - May 25th, 2018
- Enable BitLocker on USB Flash Drives to Protect Data - May 25th, 2018
- Transparent Data Encryption (TDE) - msdn.microsoft.com - April 12th, 2018
- Encryption Software Market - Global Forecast to 2022 - March 24th, 2018
- What AES Encryption Is And How It's Used To Secure File Transfers - March 24th, 2018
- Encryption vs. Cryptography - What is the Difference? - March 24th, 2018
- Energy-efficient encryption for the internet of things | MIT News - February 16th, 2018
- The Best Encryption Software - TopTenReviews - February 16th, 2018
- File-Based Encryption | Android Open Source Project - February 7th, 2018
- Beyond Encryption | Secure Enterprise email using existing ... - February 1st, 2018
- Azure Search enterprise security: Data encryption and user ... - January 26th, 2018
- Skype finally getting end-to-end encryption | Ars Technica - January 13th, 2018
- FBI chief says phone encryption is a 'major public safety issue' - January 13th, 2018
- Encryption and Export Administration Regulations (EAR) - December 27th, 2017
- Key (cryptography) - Wikipedia - December 21st, 2017
- security - Fundamental difference between Hashing and ... - December 15th, 2017
- What Is Encryption? | Surveillance Self-Defense - December 4th, 2017
- Comodo Disk Encryption Download - softpedia.com - December 1st, 2017
- Encryption - Simple English Wikipedia, the free encyclopedia - November 24th, 2017
- BitLocker Drive Encryption Overview - technet.microsoft.com - November 23rd, 2017
- The Encrypting File System - technet.microsoft.com - November 18th, 2017
- FBI cant break the encryption on Texas shooters smartphone - November 13th, 2017
- DOJ: Strong encryption that we dont have access to is ... - November 13th, 2017
- DOJ Fires Up New War With Apple Over Encryption - November 12th, 2017
- Security Awareness - Encryption | Office of Information ... - October 15th, 2017
- Data Encryption and Decryption (Windows) - October 14th, 2017
- Trumps DOJ tries to rebrand weakened encryption as responsible ... - October 11th, 2017