Since I have some previous experience with this software, I thought I'd take a moment and share some information--information which may help clarify what could otherwise be a cloud of confusion I can anticipate and envision hanging over the discussion of this GOTD. This source of potential confusion is in regard to the question, "exactly what kind of password can this PDF Password Remover actually remove?

PDF files have two kinds of passwords. One is referred to as a "User" password, or file password, and this password is used to completely lock down a file and prevent someone--not in possession of the key--to open it. Actually, the PDF is not merely locked, but the user password is used to derive a key of varying bit strength (depending on what version of the PDF standard the file is adhering to) which is in turn used to fully encrypt the PDF file (the encryption algorithm used depending, again, on the PDF version).
At this point, the file is not just locked, but completely scrambled and unreadable (except, usually, for metadata). There are no "backdoors" and the only practicable approach to gaining entry to the file, assuming you were not the owner or you perhaps forgot your own password, would be to guess the password. This is the so-called "brute force" approach, and its success can range from "dead easy" to practically impossible, depending on the complexity of the underlying password, i.e., bit strength.

The rationale for this little crash course on PDF user passwords, for those who don't know how they work, is simply to set up this next point:
today's give-away from Wondershare does NOT remove these passwords.

I repeat, if you have a PDF file which you cannot open without a password, this program will not attempt to "crack" it. This is an assumption which many people will obviously make-- and it is an assumption, incidentally, which Wondershare does nothing to discourage, or to clarify, except in the most half-hearted, finest print imaginable.

If you do have a password-protected PDF which you need to open (for whatever reason...that's your business) there exist several free programs which will attempt to crack it for you. They can use a dictionary-attack, and there are tweaks to refine the process, but it is a very much hit or miss proposition; again, everything depends on the strength of the password (and to a certain extent, the version of the PDF-standard the file implements).

So then, the question naturally becomes: exactly what password is it that Wondershare PDF Password Remover can remove? To answer this we refer to the second type of PDF password, alluded to in the first paragraph of this post. This password is a "Permissions" password (sometimes called an "Owner" password), and it dictates what you can do with a PDF once it is opened. The "owner" of the PDF--usually the file's author--can effectively say you're allowed to read my file, but not change anything, or, you can read, annotate, and comment, but you are not allowed to print any of its pages. Once these permissions are set, any further changes to the security levels are controlled by toggling this password, and it is this password which the GOTD seeks to remove. The program is normally successful at this, and a further selling point is its ability to batch process up to 200 files at one time (which is how I first became acquainted with the program, due to a particular project I was working on the time). There happens to be a few programs, and a whole slew of free online web services, which will remove security permissions from PDF files, one at a time, but I'm not familiar with any that can remove the restrictions from a whole bunch of files, en masse.

So that's it. This program can be a useful tool, but I wanted to make sure my fellow GOTD users know exactly what this app can--and cannot--accomplish, and to help them avoid any confusion and disappointment. An explanation of the distinctions between the different PDF passwords, particularly as they relate to what this program is designed to accomplish, should be a priority for Wondershare, but unfortunately it does not appear to be a concern for them. Strange, considering I know for a fact that it's a source of confusion for potential customers.

Lastly, one final critique: although I believe that Wondershare does produce a few very good pieces of software (including the GOTD, within its limitations), they engage in the distasteful practice of loading up their product pages with a large amount of obviously fake and phony customer reviews, presumably to manipulate SEO placement given the peculiar and repetitive phrases found in almost all the reviews (and I am referring to the actual "user reviews", not the cherry-picked customer "testimonials"). This does not help build confidence in a company, whatever the merit of their product, and it does their customers--and themselves-- a disservice.

Robert Garofalo  –  7 years ago  –  このコメントは役に立ちましたか？ はい | いいえ (+91)

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Wondershare PDF Password Remover 1.5.3 is not working as desired customers. I do not know the password of the PDF file to remove PDF password for Password Remover does not work unless you know the password

This user right is not effective. If you already know what the password and then use software to remove password again

So sad

IT  –  7 years ago  –  このコメントは役に立ちましたか？ はい | いいえ (+13)

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I tried to register on their webpage but it says "Multiple gift registration codes are not available for now, thanks for your participation."

user  –  7 years ago  –  このコメントは役に立ちましたか？ はい | いいえ (+13)

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If you know the user password, it means not that you are allowed to print it.
On a PDF-file there have be a user and also a owner password.
User-password just to read it.
Owner password for all actions.

Ootje  –  7 years ago  –  このコメントは役に立ちましたか？ はい | いいえ (+9)

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This file you read it and print it:
https://www.dropbox.com/s/uq19brfcr740yml/Giveaway%20of%20the%20day.pdf?dl=0
The next one just read with the password gotd:
https://www.dropbox.com/s/m2zfkgl03ye6edg/Giveaway%20of%20the%20dayProtected.pdf?dl=0
You can print, edit or something else. Then you need the owners password.
With the program of today you should do that all with the read-password.
I cannot test it, because I did not get any registration data

This file you read it and print it: https://www.dropbox.com/s/uq19brfcr740yml/Giveaway%20of%20the%20day.pdf?dl=0 The next one just read with the password gotd: https://www.dropbox.com/s/m2zfkgl03ye6edg/Giveaway%20of%20the%20dayProtected.pdf?dl=0 You can print, edit or something else. Then you need the owners password. With the program of today you should do that all with the read-password. I cannot test it, because I did not get any registration data
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Ootje  –  7 years ago  –  このコメントは役に立ちましたか？ はい | いいえ (+10)

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