An electronic envelope or e-envelope is almost like a postal Envelope in function. Where a paper Envelope privately encloses its contents like a mail message, so an Electronic envelope privately encloses its contents like an e-mail message. Currently, e-mail not enclosed in an electronic envelope is like sending a Postcard in the standard postal mail system. Just like the postcard, where any postal worker handling the mail can read its contents, any server operator and programs from governments can read your E-mail (also "email"). E-mail is more or less an electronic postcard (or E-postcard)in function. ("e-" = electronic as in e-mail (email), e-envelope or e-postcard.)
A missive, composed personal or business letter or a document is placed into a postal envelope, usually sealed, addressed and mailed through the Postal system. The envelope can be intercepted and the interceptor of the mail can open it, read it and understand it providing the interceptor can read the language, understand the terminology or break any encryption of data. Most paper mail does not have this happen to it unless a government has a specific interest in a person's mail. When the letter or envelope arrives the recipient opens the sealed envelope, takes out the contents and must have the understanding and knowledge to read it.
In the postal system there is no way of scanning the contents of the envelopes passing through the system for specific key words or text enclosed in the envelope. But in the Internet world, e-mail can be scanned by governments, ISP's, companies, Internet traffic servers, bots, by key words, names mentioned, etc.
An e-envelope is an electronic e-mail with a message or data which has been encrypted into a data packet. The Plaintext Internet address header is at the top of the e-mail message and the encrypted message or data packet is in the message area. An e-mail message with a fully encrypted data packet in the message area is an electronic envelope or e-envelope. The message can be intercepted and the interceptor of the e-mail can read it with the right Decryption method, Password or Passphrase. The ease of decryption depends on the strength of the Encryption method. Cryptographically strong methods usually use Passwords or Passphrases to protect the Key (cryptography). Weak Passwords or weak Passphrases make the e-envelope easier to open by e-mail handlers or snoopers. Strong passwords or pass phrases can make the opening of these electronic envelopes virtually impossible to open except by its intended recipient. The loss of the key, a forgotten password or pass phrase can also yield these e-envelopes impossible to open. It is always a good idea to make the e-envelope open able by both the sender and recipient so the message can be re-sent to a person who has lost the key, or forgotten a password or passphrase.
An e-envelope can also be an encrypted communication between parties using Internet browsers that can use https. The encryption/decryption engine on a special Internet server like the free Hushmail Express at www.hushmail.com can be used without any resident software on either computer. PGP (or Pretty Good Privacy) has been an Internet Standard since the early 1990s. It is freely available for most common computer platforms. One source is a free "trial" version at www.pgp.com that has been available for a number of years. When you get to that website as it frequently changes, look for the individual and or small business versions and download it as an individual for personal use. After the trial version expires the automatic features cease to function, but the functions that allow you to encrypt the text of an e-mail or other documents on your computer remains functional. It is easy to use it in manual mode after that for free. Another version of PGP is freely available as GNU Privacy Guard. Most IT (Information technology)workers are familiar with it and it has been an Internet standard since the 1990s. It always has a free version, but there is a small learning curve in learning how to use it. Just download the personal or small office versions and after 30 days the commercial version reverts to the free version usable for e-mail. There are other such free Internet encryption engines available which can encrypt/decrypt your e-mail message text. Whatever you use, the other party or person must have the same compatible software as well, unless using self-decrypting archives and mailing them as an e-mail attachment. There must be strong trust between the sender and the receiver that the self-decrypting archive is from them because it is an executable (.exe)program file with the encrypted message in it. A phone call or Internet Chat message between two persons that have known each other for considerable time is a good way of being able to tell if what you are receiving is trust worthy to allay fears it is a virus or other malware. It should be sent and expected in a short time frame of just a few minutes so there is less chance of someone pretending to be the other party sending a virus. Various PGP programs can do this, but a pass phrase must be set up between the sender and receiver to open the message. Some e-mail providers will not let these types of files through their systems as attachments because the Internet Service Provider does not know if such a file is a virus or not. In that case that file might have to be enclosed in an industry standard Zip (file format) that in itself cannot cause harm by passing through server or e-mail provider system on the Internet. High end "pay for" providers often have a way for these files to get through but many of the free services do not. You must check with the e-mail providers you are using or experiment. Another "free trial" use and pay for provider is www.s-mail.com in Ireland, but the computer you are using must be able to download and store a java program. Many public library and employer computers have security features enabled to prevent this. But using a personal laptop or wireless PDA in an employer's, library's, Internet Cafe's or other Hotspot (Wi-Fi) public use area often do not have these limitations.
Hand calculated pencil and paper ciphers or codes when typed up in a digital form on a computer can also be considered electronic envelopes. Some simple Substitution ciphers or transposition ciphers or combinations of both, using the common ASCII (American Standard Code for Information Interchange) computer characters can also be used. These characters are found on the standard Romanized Latin alphabet text keyboards in English and other European countries which are used to compose Internet messages encased in electronic envelopes.
- The electronic envelope, by Misra, Santosh K., Publication: Internal Auditor, Date: Dec 1998,
- An Electronic Envelope, same link in Internet Archive WAYBACK MACHINE
- How electronic encryption works, same link in Internet Archive WAYBACK MACHINE
- Privacy on the Internet, David M. Goldschlag (firstname.lastname@example.org), Michael G. Reed (email@example.com), Paul F. Syverson (firstname.lastname@example.org),
- "Glossary for IT security terms", "PKCS#7", electronic envelope, same link in Internet Archive WAYBACK MACHINE