First of all, never use a free or paid, web-based service for securing your messages.
The simplest way for such a task is to compress the file with WinRar, 7-zip, Archiver etc., using a secure password of let say some 13 numbers, symbols, upper and lower case characters.

Luis tarafından yorumlandı  –  5 years ago  –  Bu yorumu yararlı buldunuz mu? evet | hayır (+15)

Çevir

Most not both the sender and receiver install this software to be able to use it? Or can the receiver decrypt online?

Leif Oliversen tarafından yorumlandı  –  5 years ago  –  Bu yorumu yararlı buldunuz mu? evet | hayır (+11)

Çevir

I don't like the fact that the send and receiver should be using the same software. Since this is a limited time offer, I could not expect to be able to gather a list of people this very same day and ask them to download it. What if I think of someone a few days later that I might want to send encrypted messages. I am screwed by then. The receiver of the encrypted message should be able to enter the decryption code to be able to see the message no matter what platform is used. Most people have more other important tasks to do before downloading this time limited software before the time limit expires. Therefore, I do not feel that this is a software worth downloading.

Starchild tarafından yorumlandı  –  5 years ago  –  Bu yorumu yararlı buldunuz mu? evet | hayır (+10)

Çevir