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.[1]
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."[2] 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.[3]
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.[4] 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.[5] 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.[6] 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'[7]
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.[8]
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.[9] 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.[10]
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.[11]
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.[11][12]
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Email encryption - Wikipedia
- WhatsApp overhauling status tab with encrypted Snapchat Stories-like feature - 9 to 5 Mac [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- GOP demands inquiry into EPA use of encrypted messaging apps - CNET [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- Encryption Apps Help White House Staffers Leakand Maybe Break the Law - WIRED [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- World Wide Web Creator Calls for Internet Decentralization & Encryption - The Data Center Journal [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- What It Means to Have an 'Adult' Conversation on Encryption - Pacific Standard [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- Confide in me! Encryption app leaks sensitive info from Washington DC - SC Magazine UK [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- Gmail v7.2 Prepares to Add Support for S/MIME Enhanced Encryption - XDA Developers (blog) [Last Updated On: February 26th, 2017] [Originally Added On: February 26th, 2017]
- Top 6 Data Encryption Solutions - The Merkle [Last Updated On: February 26th, 2017] [Originally Added On: February 26th, 2017]
- Your Guide to the Encryption Debate - Consumer Reports - ConsumerReports.org [Last Updated On: February 26th, 2017] [Originally Added On: February 26th, 2017]
- Google helps put aging SHA-1 encryption out to pasture - Engadget [Last Updated On: February 26th, 2017] [Originally Added On: February 26th, 2017]
- Decipher your Encryption Challenges - Infosecurity Magazine [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- How the Politics of Encryption Affects Government Adoption - Freedom to Tinker [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- How Encryption Makes Your Sensitive Cloud-Based Data an Asset, Not a Liability - Security Intelligence (blog) [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- Set up VMware VM Encryption for hypervisor-level security - TechTarget [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- How The Media Are Using Encryption Tools To Collect Anonymous Tips - NPR [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- Encryption patent that roiled Newegg is dead on appeal | Ars Technica - Ars Technica [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- Research proposes 'full-journey' email encryption - The Stack [Last Updated On: March 1st, 2017] [Originally Added On: March 1st, 2017]
- Database-as-a-service platform introduces encryption-at-rest - BetaNews [Last Updated On: March 1st, 2017] [Originally Added On: March 1st, 2017]
- Encrypted Messaging Service 'Signal' Adds Video Call Option - Top Tech News [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- Germany, France lobby hard for terror-busting encryption backdoors ... - The Register [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- How to Send Encrypted Nudes, a Guide for the Discerning Lover - Inverse [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- Ironclad Encryption Corporation Announces New Ticker Symbol OTCQB: IRNC - Yahoo Finance [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- The Best Email Encryption Software of 2017 | Top Ten Reviews [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- No, you shouldn't delete Signal or other encrypted apps - TechCrunch [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Best encryption software: Top 5 - Computer Business Review [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Encryption Backdoors, Vault 7, and the Jurassic Park Rule of Internet Security - Just Security [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- That Encrypted Chat App the White House Liked? Full of Holes - WIRED [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- What the CIA WikiLeaks Dump Tells Us: Encryption Works - New York Times [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Snake-Oil Alert Encryption Does Not Prevent Mass-Snooping - Center for Research on Globalization [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Customer Letter - Apple [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Don't Let WikiLeaks Scare You Off of Signal and Other Encrypted Chat Apps - WIRED [Last Updated On: March 12th, 2017] [Originally Added On: March 12th, 2017]
- BT to offer customers encryption service for data - Capacity Media (registration) [Last Updated On: March 12th, 2017] [Originally Added On: March 12th, 2017]
- Encryption - technet.microsoft.com [Last Updated On: March 12th, 2017] [Originally Added On: March 12th, 2017]
- Use FileVault to encrypt the startup disk on ... - Apple Support [Last Updated On: March 12th, 2017] [Originally Added On: March 12th, 2017]
- Viber launches secret chats to go beyond encryption - SlashGear [Last Updated On: March 13th, 2017] [Originally Added On: March 13th, 2017]
- Zix wins 5-vendor email encryption shootout - Network World [Last Updated On: March 13th, 2017] [Originally Added On: March 13th, 2017]
- A lesson from the CIA WikiLeaks dump: Encryption works - The Seattle Times [Last Updated On: March 13th, 2017] [Originally Added On: March 13th, 2017]
- What the CIA WikiLeaks Dump Tells Us: Encryption Works - NewsFactor Network [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- Panicked Secret Service Says It Lost Encrypted Laptop But It's Fine, Everything's Fine - Gizmodo [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- Google Cloud adds new customer-supplied encryption key partners ... - ZDNet [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- Preseeding Full Disk Encryption - Linux Journal [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- Bypassing encryption: 'Lawful hacking' is the next frontier of law enforcement technology - Boston Business Journal [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- SecurityBrief NZ - Gemalto introduces on-prem encryption key solution for 'highly regulated' organisations - SecurityBrief NZ [Last Updated On: March 21st, 2017] [Originally Added On: March 21st, 2017]
- 'Always Be Concerned': US Court Slaps Down Fifth Amendment Defense of Encryption - Sputnik International [Last Updated On: March 21st, 2017] [Originally Added On: March 21st, 2017]
- Quantum Key System Uses Unbreakable Light-Based Encryption to Secure Data - Photonics.com [Last Updated On: March 21st, 2017] [Originally Added On: March 21st, 2017]
- Wikileaks Only Told You Half The Story -- Why Encryption Matters More Than Ever - Forbes [Last Updated On: March 21st, 2017] [Originally Added On: March 21st, 2017]
- EPA Sued For Withholding Info On Encrypted Text Messages | The ... - Daily Caller [Last Updated On: March 22nd, 2017] [Originally Added On: March 22nd, 2017]
- Opinion Data encryption efforts ramp up in face of growing security threats - Information Management [Last Updated On: March 22nd, 2017] [Originally Added On: March 22nd, 2017]
- Bypassing encryption: Lawful hacking is the next frontier of law enforcement technology - Salon [Last Updated On: March 22nd, 2017] [Originally Added On: March 22nd, 2017]
- NeuVector Announces Container Visualization, Encryption, and Security Solution for NGINX Plus - DABCC.com [Last Updated On: March 23rd, 2017] [Originally Added On: March 23rd, 2017]
- Is encryption one of the required HIPAA implementation specifications? - TechTarget [Last Updated On: March 23rd, 2017] [Originally Added On: March 23rd, 2017]
- Paper Spells Out Tech, Legal Options for Encryption Workarounds - Threatpost [Last Updated On: March 23rd, 2017] [Originally Added On: March 23rd, 2017]
- Encryption debate needs to be nuanced, says FBI's Comey - TechTarget [Last Updated On: March 25th, 2017] [Originally Added On: March 25th, 2017]
- Comey Renews Debate Over Encryption - 550 KTSA [Last Updated On: March 25th, 2017] [Originally Added On: March 25th, 2017]
- UK minister says encryption on messaging services is unacceptable - Reuters [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- The why and how of encrypting files on your Android smartphone - Phoenix Sun [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- UK targets WhatsApp encryption after London attack - Yahoo News [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- Critical flaw alert! Stop using JSON encryption | InfoWorld - InfoWorld [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- SecureMyEmail is email encryption for everyone - TechRepublic - TechRepublic [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- Apple iOS 10.3 will introduce encryption which makes it MORE difficult for cops and spooks to crack into ISIS nuts ... - The Sun [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- How to Analyze An Encryption Access Proposal - Freedom to Tinker [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- Questions for the FBI on Encryption Mandates - Freedom to Tinker [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- Justice Department anti-terror chief keeps pressing on encryption - Politico (blog) [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- UK government can force encryption removal, but fears losing, experts say - The Guardian [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- Encryption FAQs [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- Why isn't US military email protected by standard encryption tech? - Naked Security [Last Updated On: April 9th, 2017] [Originally Added On: April 9th, 2017]
- How have ARM TrustZone flaws affected Android encryption? - TechTarget [Last Updated On: April 9th, 2017] [Originally Added On: April 9th, 2017]
- Keeping the enterprise secure in the age of mass encryption - Information Age [Last Updated On: April 9th, 2017] [Originally Added On: April 9th, 2017]
- Lack of encryption led to Dallas siren hack - WFAA [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Internet Society tells G20 nations: The web must be fully encrypted - The Register [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Make Encryption Ubiquitous, Says Internet Society - Infosecurity ... - Infosecurity Magazine [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Can we encrypt the web while giving governments a backdoor to snoop? - SC Magazine UK [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Why we need to encrypt everything - InfoWorld [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Hacked Dallas sirens get extra encryption to fend off future attacks - Computerworld [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- SHA-1 Encryption Has Been Broken: Now What? - Forbes [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- Hewlett Packard Enterprise touts encryption tool for federal clients - The Hill [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- Encryption on the Rise in Age of Cloud - Infosecurity Magazine - Infosecurity Magazine [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- Lawmaker Pushes Bill That Requires Encryption by Pennsylvania State Employees - Government Technology [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- Disk encryption - Wikipedia [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- The apps to use if you want to keep your messages private - Recode [Last Updated On: April 15th, 2017] [Originally Added On: April 15th, 2017]