Don't try to encrypt files. Create an encrypted container, and store files securely inside it.
What is an encrypted container?
It's a file which you can store other files inside. It's encrypted: you can only get the files inside with the right software, and the right password.
When it's closed you can copy the container (it's a file), rename it, delete it, or even attach it to an email message.
What do you use them for?
Use them for protecting information that only you are able to access, or for sharing files securely.
An encrypted container is much like any other file:
- you can copy it, rename it, move it to a different folder
- you can delete it by moving to the Recycle Bin or "Trash"
- you can copy the encrypted container onto a USB stick or portable storage device
- you could place it in shared file space, and allow other people access to it
- you could even attach it to an email message
When you open it, it decrypts and becomes a place just like a disk or a folder, where you can store or use files. Only people with the right software and password can open it.
Which software to use
The list below shows a list of software you can use, and provides links:
- Windows: 7zip for windows: works only on Windows computers, compatible with .ZIP format
- Apple Mac: iZip for Mac OSX: works only on Apple Macs, compatible with .ZIP format - Some users have reported crashing issues with iZip when using MacOS10.13 and 10.12.
- Apple Mac: The Unarchiver for Mac OSX: works only on Apple Macs, compatible with .ZIP format
- Apple Mac: an encrypted disk image : works only on Apple Macs
- Veracrypt: works on any Windows, Apple Mac or Linux computers
You need to use the right software, and the right password. You can't decrypt a "7Zip" container, using Veracrypt.
If you are sharing encrypted files with people using other operating systems, then make sure you can both use a compatible file format such as .ZIP.
If the person you want to share with is using the same operating system as you, 7zip and iZip will do the job just fine.
Remember: When sending an encrypted file to somebody, do not send them the password using the same method. e.g. phone your recipient with the passoword if you sent the encrypted document by email.
Sharing securely ("telling people the password")
Strictly speaking it's not really a password. It is actually a "decryption key". You choose and use decryption keys, in the same way as passwords. (Except of course, that you never tell anyone a password.)
When sharing (or giving someone) an encrypted container, the easy (and safe) way to them know the decryption key, is to tell them face-to-face, or phone them. Don't send the decryption key by email.