What is encryption and PDF encryption?
Encryption is the use of a mathematical system (algorithm) to make information secret from anyone not authorized to use it. Encryption uses a secret key to scramble information in files so that only those with the correct key can view them. PDF encryption is therefore the encryption of PDF files, the result of which is an encrypted PDF file.
Encryption keys are sometimes taken from passwords, but passwords are a poor choice for encryption keys – see PDF password protection. It does not matter what the strength of the encryption algorithm is if the implementation is not secure.
Why encrypt PDF files & documents?
There are many reasons why you would want to encrypt PDF files.
The information in the PDF document is confidential and only a restricted number of people should be able to see it. This could include training courses, price lists, bid documents, takeover plans, healthcare records, and so on. The information is valuable – you sell it – perhaps a newsletter, or an analyst’s report, or a consulting report or a periodical or a book. You obviously don’t want to give it away!
If you don’t encrypt the PDF file then anyone can read it and the value of your information is lost. But if you are going to encrypt PDF files then you need to use PDF encryption software that uses a reliable encryption method.