Just thought I'd run this idea past far more experienced heads.
I've made a desktop application in java 8. It is a niche app that will be sold via a single website. The market is individuals in a specific work environment who would not be "tech-savvy", and who are either on or chasing a 6-figure salary. My client, the publisher/vendor anticipates sales of maybe (don't laugh) 50-100 per year... so it's very niche. The retail price of the software, because of the low volume and niche setting, is to be around $100. So it's just a pet project that maybe helps to fund the family holiday at the end of the year.
The target customers will be on a high enough salary to not worry about paying the premium for the software (tax deduction anyway), which will directly enhance their ability to make more money, but they also have a reputation for having few scruples, and would generally not care about casually copying the software and giving it to their work mates.
The software will not be able to connect to the internet, so it's stand-alone, isolated.
So I need a copy protection scheme that is simple, not onerous to the end user and, due to it's target market and low volume, doesn't need to be "hacker-proof".
So this is what I've come up with:
Vendor has a "password" generator, that uses a simple algorithm, an
adaptation of the Luhn formula, that is capable of a few million
unique 8-char strings, out of a total possible pool of a few hundred
billion. So a valid password would be very hard to guess. Software
downloaded, generated password emailed to customer.
Software checks the "password" for validity, using a checksum-related
scheme. If valid, software is unlocked, and an invisible file is created somewhere generic on the hard drive, which flags that the software install is valid.
A different invisible file is written to the parent folder of the
software, which contains the provided original password. This is storage for passwords that have already been used, and are therefore invalid.
Next time the software is launched, it checks for the existence of
the validated-flag-file-- if it exists, then the software launches,
otherwise it asks the user to contact the vendor for a new password.
Whenever a user needs to type in a new password, the software checks the "invalidated passwords" file. If the user types in the original password, the software won't launch, because it's invalidated. But the file also needs to exist in the parent folder, so it cant be deleted either.
The idea is that if a casual user copies the software either by itself, or with its parent folder the software wont work on another machine, even if they have the original password, but if they are legitimate (registered user who needs a copy for working at home etc) then they can contact the vendor for a new valid password, that will then work on the new copy.
Hope that makes sense.
Comments, suggestions?
Full disclaimer: I work for Link Data Security and is your competitor, but this doesn't stop me from giving a few advises, as badly made protection damage the whole copy-protection community.
First of all you need to look into how hackers crack your program and try to deffend against their usual attacks. That would be debugging, changing your code when testing for validation, copy of key/validation-file and many more. This is the things I can remember from the top of my head. There will always come new cracking methods, due to hackers being very creative people.
If I was you I would try to run my program in a sandboxed enviroment, see what it does. Then make sure that files created or such doesn't help the hacker to find a good way to hack your protection.
Next time the software is launched, it checks for the existence of the validated-flag-file-- if it exists, then the software launches, otherwise it asks the user to contact the vendor for a new password.
From your description of your program I find it worrying that copy/move of your validated-flag-file to a new computer seems to break the copy protection. Also finding invisible files is the first thing a new hacker will learn, so this is the same as no protection.
A colleague of mine wrote a tutorial on what to take into consideration when making copy-protection, maybe this will help you on your way to being a copy-protection expert: All About Copy Protection
Related
I've used plenty of cocoa demo apps that stop working after 3 days or a month or so. How do they do that? What's the best way? Also, what are the limitations?
(Disclaimer: I've never made a trial version before, only read up on the subject and used a bunch of them.)
The limitations all come from the fact that anything on the user's system, the user can modify. So:
Clever cheapskates may alter your app's executable to stub out or otherwise defeat any check you make.
You have to store the amount of time used (or, more lazily but not as user-friendly, the date they started using your app) somewhere. Wherever you store it, the user must be able to change it (since your app runs as them), which means that if they find it, they can reset the clock.
It isn't possible if you run in a sandbox, unless you store the aforementioned time-tracking data in the user defaults or the Keychain, either of which might as well be in plain sight, or request the temporary exception entitlement for writing anywhere on the file-system. Time-limited trials can't be in the App Store anyway, but if either the App Store or sandboxing becomes required in a future version of Mac OS X, your time limit will break, and we can only hope it doesn't prevent the user from using your application entirely.
There's also the matter of handling payments. One way would be to sell the app in the App Store, without any trial-enforcement code, and distribute a separate build yourself that always enforces a time limit. If you do handle payments yourself, you need to store a record of the user's license on the user's system, and you need to check that license. This then becomes vulnerable to the same problem: The user may forge a license or “borrow” (e.g., download from a warez site) someone else's.
The upside, of course, is that the user has some amount of time to try the application for free without having to cough up any money, so at the end of that time (if your application is good and fills their needs), they'll be more likely to buy.
At the end of the trial period, you have a choice of what happens:
Lock the user out of the application entirely.
Cut out features. Acorn does this.
Let them open documents, but not save or print. (You can block screenshots, but then good luck handling bug reports.)
Let them save or (if applicable) print, but degrade part or all of the document in some way. For visual creations, such as images, a watermark may work. For audio, you can limit the sampling rate to something unpleasant like 20 kHz or less. (There's a case here for having your own proprietary format that you always handle losslessly, and only degrading exports to common formats such as TIFF, JFIF, or AIFF.) Fission does this.
Just nag them. (Can be combined with any of the above.)
Nag them and put a delay on the user's ability to dismiss it. You can even increase the delay the longer the user goes without paying.
One good alternative to the trial period is to have a separate “free” version with fewer features (or with ads). This is especially common on both App Stores.
Another consideration is whether the trial period is days used or days since first use. The latter is easier to implement, since you just record the date of first use and do subtraction. The former is more user-friendly, as it does not punish the user for launching the app once, playing with it for five minutes, and coming back to it for a real trial 31 days later.
You can also implement a limit on number of launches. It's as simple to implement as days-since-first-use, but doesn't punish only playing with the app once.
Some users just won't pay. Some users will do practically anything to not pay.
So you need to strike a balance. You need to provide a basic level of difficulty so that the laziest cheapskates cannot simply defaults write com.example.yourapp DaysSinceFirstUse -int 0 and keep using your app forever, while not making your app so onerous to try out (much less pay for) that they don't.
So here are some things not to do:
Attempt to enforce equality between the name of the user on their license (entered at purchase) and their name on their account or in the Address Book. There are a dozen different ways to write any name, and some people have multiple names (through marriage, aliases, legal name-changes, multiple languages, Star Trek fandom, etc.), so this or anything like it is a bogus check that will upset more legitimate users than discourage pirates.
Hold the user's data hostage. See my above point about the merit of a proprietary format that you always handle losslessly. If you do always degrade output during trial, make that absolutely clear up front in the app's on-launch “This is a trial version” dialog.
Require an internet connection. Not everybody has one (that can connect to arbitrary servers), and not everybody has one all of the time. Learn from the games industry: Don't alienate your users.
Install any sort of copyright enforcement software that runs in the background and/or is in a separate place from your application. Users will rightly hate you for this.
As for how to do it, here's what I recommend:
Implement a “days of actual use” check. This can be a selling point. It warms my heart when a trial explicitly says it uses this kind of check.
I'd say store it in hours. On launch, get the current number of hours from wherever you store it. Add two hours and write it back (so the user can't force-quit your app to defeat this). On quit, add the real number of hours since launch to the originally-read number and write the revised number back.
Store it in an invisible file in Application Support. Encrypt it (again, you want to defeat casual piracy), but don't waste too much time bulletproofing it. Remember, your app must contain everything to both encrypt it (to keep track) and decrypt it (to perform the check), so a sufficiently determined (and educated) cheapskate can break this no matter what you do.
On launch, get the current number of hours from wherever you store it and test whether it's over the limit. (If you take my add-two-hours-right-away suggestion, do that after you test against the limit.) 30 days is 30×24=720 hours. If it's over the limit, enact your trial-expired measures.
If you sell the software yourself, use symmetric public-key encryption for the license file. I think AquaticPrime does this. You encrypt licenses with your private key, and distribute the public key in the app, which uses the public key to decrypt and check the license. Practically unbreakable. You send license files to customers by email using the email address they provide at purchase. (Tell them that they will receive the license by email so they don't enter a made-up address.)
If you do this, make sure you test entering the license, both before the trial ends and after it ends.
Do the trial check only if there is no license.
If you can sell your app in the App Store, I recommend you just do that. If you want to also distribute a trial version yourself, do that with no licensing code in place, so the trial check simply happens unconditionally. The App Store version, of course, does not need (and must not have) a trial check.
Watch this. (Note: It pre-dates both of Apple's App Stores.)
In general, they save a count of days/hours/whatever used somewhere, e.g. in the app's user defaults.
Since it's fairly easy to change an app's user defaults, some write a simple hash to the file that has to match the number of days used. If not, they expire the build right then and there because a user obviously just mucked with that setting. Others keep several copies of the number of days used counter. If one is missing, they restore it based on the lowest number in one of the other locations.
Good locations are invisible files in locations the user wouldn't expect, maybe named so they look similar to a file by another app or a system file. But be careful that you don't litter files across the file system that then give the other app they look like a bad name. Also worth considering is writing a resource into a file's resource fork, where most people don't look anymore these days (one of your files! Another app or the system may replace their file and strip your info, or may use the same resource type and cause a collision).
Chances are, a casual hacker will try to edit the user defaults and then give up. A dedicated hacker will keep going no matter how much effort is put in the protection scheme, so it's not worth spending too much time on protecting it.
Some app developers instead generate a license key that has an expiration date in it and make the app refuse to run without a valid license key. There's a nice article by Allan Odgaard on how to sign information using OpenSSL (make sure you use LibreSSL or CommonCrypto.framework these days, which are very similar) to get the expiration date to your user without them being able to edit it: http://sigpipe.macromates.com/2004/09/05/using-openssl-for-license-keys/
Based on your ideas I made a short proof of concept in Java using Elliptic Curve Cryptography to generate a UUID on start up and then sign that UUID with ECC to create a registration key. The code is here if anyone wants it.1
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We plan to sell a Windows portable application. By 'portable' I mean that it can be run from any Windows computer without installing it. For example from an USB stick etc. However the application while (theoretically) it can work anywhere, is targeted to LAN environments.
What solutions do you see that while keeping this advantage (in a more or a lesser degree) to still make money from it?
PS: The application is/will be written in Delphi.
If you are offering your product for sale and not for free, then you will most likely make money from it. If what you are asking is how to maximize the income and prevent piracy, then that is a more specific question.
The key to making money with software is to make the purchase route less painful then the piracy route. Usually the biggest hurdle to purchasing software is the price tag (but not always, some people just will never buy software and always pirate, but you can't do anything about that). And the biggest hurdle to piracy is some sort of DRM scheme, which is actually the second largest hurdle to purchasing software. Often times DRM only annoys the legitimate purchases, while the pirated version has all the DRM removed with less effort then you spend to put it in. Thanks to the wonder of electronic duplication, once the DRM is removed, then everyone can have a DRM free copy.
So you want a solution that only annoys illegitimate usage, but not legitimate purchases. This is much harder to do then expected.
Depending on the price tag for your software you might consider deploying it on a keyed USB drive (i.e. Dongle or USB stick with some special key). Then it is portable, but only on the hardware you provide. The user never has to worry about a secondary authentication scheme, and the DRM only becomes an issue when the hardware (which is harder to duplicate) is changed.
You say that it is only for a LAN environment, which doesn't necessarily mean that the computers will have internet access (and if they do, they probably have a proxy requirement) which means "phoning home" will be problematic. If you want the product to only be used on a specific LAN then you might require a license server to be installed on the LAN. Then the software could always check with the license server to make sure it is authorized. That won't work if you want it to run on multiple LAN's though.
Conversely if your price is low enough then most companies and people would rather buy the correct licenses and not risk the piracy. In actuality, depending on your clientele, most people will prefer legitimate licenses when they can, and DRM can actually discourage them from buying licenses.
Some alternatives:
Use a dongle, where the user of the software must plug in the dongle before your application can work.
At startup read a configuration file and if this is invalid or missing, halt the application or reduce its functionality. The configuration file should contain information about the user or company that licensed your software, and also a checksum to prevent users from changing the file. With such a file, serious companies are less likely to distribute this configuration files to others. Of course, you should then create one such configuration file per user that licenses your software.
Optionally, include specific computer information (type, memory, bios date, system guid, ...) that prevents the application from being run on other computers.
Make sure you make money from the service you can deliver, not only from the software you are selling. This service can include: providing upgrades, taking suggestions for improvements, assisting with problems, helping with domain-specific knowledge, ...
You can use some sort of license file and a "phone home" option that makes sure the same license is not used at more than one place concurrently.
If you have a large ordfer, you could try to get a memory stick with a special serial number and/or value in it that you can read out in the software (eg the exe must reside on a special memory stick)
Please note that a lot of users get quite annoyed by these things (we've used the first option)
Also please note that if commercially interesting, your app will be hacked. Make sure the effort someone has to take outweighs the profit the could make
One approach that also helps some is by custom branding. Each copy you sell would have compiled into it the name of the company it was sold too, which can be displayed as part of the splash screen as well as the about screen (along with a button to view the license terms). Most often this branding is done by using an external file which contains the information encrypted that when placed in the same directory as the executable is used to unlock the application as well as possibly provide additional functionality.
Unfortunately with todays software firewalls, most of the simple solutions to disallow running multiple copies on a network are not practical while still maintaining true portability, or requiring internet access to a server that you fully control.
Yes, piracy is a problem, but if you continue to offer great support and there is an additional "visible" benefit to purchasing, you can help offset this in your favor.
If you need trial protection, you can count uses/days if you have any sort of database where the user will have invested time and data, and won't want to lose it. Just encrypt the counter and place in the database somwhere. The user can then only reset the trial by wiping out the database. Depending on the type of app, this may be effective, or not.
Another approach is to not have a portable trial at all, but offer it as an incentive for purchase. i.e. conduct the trial on the desktop, and when they purchase a license, they get a license key that allows it to run on portable devices.
I recommend the PortableApps.Com framework for launching your app. It's free. You need to make your "launcher" open-source, but not your app itself. You can still run on a bare drive, if you follow their pattern.
I am working on making educational CDs. I require medium level copy protection code which may not be easily breakable by "non experts", similar to that in game CDs, so you have to have the CD in the drive while playing and have to enter key while installing it.
I think CD copy protection mechanisms MUST BE STAYED AWAY FROM! They cause your software installations recorded on such CDs to run incorrectly on many devices. What such protection mechanisms do is inserting BAD TRACKS on your CD hoping that the CD copying program will choke on them. However, the driver of the CD drive may choke as well. You're better off with an additional privacy prevention scheme.
Whatever trick you'll find, someone smart will find away around it.
Decide first for what kind of users you want to protect your software:
For casual users and kids, it might be enough to check the volume id
For more advanced users, consider using commercial protection software like SecuRom
You may also consider using a registration via Internet, where you provide your users with a 'license file' in which their username (and maybe some other configuration information) and a checksum is stored, and which should be saved on their PC. Users and especially companies are then less likely to hand out this configuration files to others, as this file simply states "I handed out my license to someone else, so if you want to sue someone, sue me".
Many games use third-party software such as SecuRom for this.
If you do not require that level of protection, you can simply check for the presence of certain files on the CD. That will stop people from running without having the CD, but not from copying the CD itself.
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I have a game that I'd like to sell with the following system: give away a demo (say, with the first few levels) and sell the full version. I'd like to make the transition to the full version as seamless as possible for the user. I've never sold anything before online, so I'm not sure how that would work (even if there were no free demo).
This seems like a very common issue, so I'd imagine there's a standard solution. I'm writing in C++, targeting Windows, and my installer is generated by NSIS.
There are two options:
A separate demo and full version. Your ecommerce provider will send the full version to people who buy it.
A demo that is unlocked by a registration key or online activation process. Registration keys can be generated on the fly (or taken from a pre-generated list). Ecommerce providers can then send the keys to customers immediately after purchase.
Both approaches have their pros and cons.
Separate full version
Smaller demo file, saves bandwidth
Less technical support required for customers who buy full version (in my experience)
Two builds of the game, more testing
Harder to distribute updated versions to customers - need to keep a login for each customer or a secret URL that expires after a few days.
Unlockable demo
Contains all assets, may waste bandwidth
Easier to distribute cracked version (pirates can distribute a 10KB patch or reg key and link to your demo file, more bandwidth waste)
Single build, less testing
Easy to distribute updated versions (everybody can download the same public version)
Regarding a "general" solution, look around for commercial DRM wrappers such as this one. Some game portals/publishers also require that you use their own wrapper.
Don't ship your full product as a demo that can be activated. This way you don't eliminate piracy (which will still be something you will have to deal with) but at least you remove the possibility of someone just downloading the demo, cracking it, and spreading it around (or even just a cracked executable). They would at least have to buy the full version first.
As for checking a legit customer is using the software, you can indeed do some online authentication as Danny suggest but note that this will only stop people from using your online services and it often is just a matter of time before a qualified cracker/reverser makes sure that your product's offline features can be used without purchase.
By not shipping the full product immediately, it does make upgrading a little harder, but there are ways around this, ex: Updater that only works after online authentication.
If you develop it correctly you should be able to have a checking mechanism after the Xth level. This checking mechanism could basically hit a registry key. This registry key could have some encoded information which was generated by your program. The key could basically represent an MD5 hash (or SHA-1 or SHA-2 if you really concerned with high security) of the installed machine MAC Address, the first and last name, so and so forth. When someone purchases the game, you have them input that data in a form and then generate a code to send along to the user to unlock the game. You could even take that same algorithm and put it on your ASP.NET website and automate the key generation after a purchase has been made.
My 2 cents:
Dont spend too much time devising methods against piracy. Use simple serial generator mechanism to unlock the game which user can enter manually during the execution.
I would say have a single build which can switch to trial mode or full based on the serial key entered. This will reduce the overhead of maintaining two separate code.
It is a personal opinion, that people who really buy software at first place will buy your game no matter how many pirated versions are available. So make registeration purpose as simple as possible which will deter a normal user from cracking it and at the same time easy to use. Hackers will crack it no matter what protection you use it. Otherwise we wont see the pirated copies of microsoft/adobe products etc who spend so much on making their products piracy free. No matter what they charge, people do buy it. Its the quality of the product which will encourage your users to buy your product.
Also, try not to impose locks on your software like using MAC address etc for generating the serial numbers etc. Online activation may be a good idea but remember people are skeptical as to what information you try to transmit while activation. Also you might have to provide an alternate mechanism for offline activation if your customers dont have internet connection or work in separate LAN.
Once you see that you game is getting popular and you see more pirated copies with users, you may invest more time and money on developing anti-piracy techniques.
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I am thinking of implementing a good licensing mechanism that has a good resistance against piracy. The required mechanism should not use an internet connection at each and every time the software is used. I am thinking of a mechanism based on hardware IDs etc. Do you guys have any better suggestions? What are the parameters/algorithms/characteristics that I need to concern to make a hack proof license mechanism?
Ideally you need something that is OS independent.
I would recommend that you embed the license protection within your code or wrap your application within it in such a way that it cannot be run without the copy protection code having run first.
It would be best if your application needs a license key file in order to operate and that this isn't generated locally.
One way of doing this is that your application generates some form of image code based upon the hardware on it's initial run. This is supplied to you and in return you supply the license key which will allow the code to run. Best to base the hardware image around CPU and motherboard as these will change the least often.
Your app. should check against hardware image and license key whenever it is run.
If you want your app. license time limited then it should also keep track of how long it has run and embed it within the license key file.
Don't forget to encrypt the license file.
Also don't forget to make it more difficult to reverse compile your executable by use of a dotfuscator or similar.
Check this question: What copy protection technique do you use?
It also links to other related questions.
First of all, nothing is hackproof, so i wouldn't spend too much time on protecting your software.
The downside of a mechanism based on hardware IDs is when a user buys a new computer or upgrades most of his computer he needs to update the key too.
HWHash is a pretty good HardwareID implementation, but i guess there are more (free) solutions.
At work we use Hardlock and Hasp keys, but these are usbkey solutions which are not very efficient for small applications.
I am thinking of implementing a good licensing mechanism that has a good resistance against piracy. The required mechanism should not use an internet connection at each and every time the software is used.
Then how about a periodic online check of the licence?
When the user logs in the first time, the user verifies the install against his account and a licence file is stored on the users PC. This licence file is encrypted and contains all the data needed to uniquely identify the license. This is all stored on your server.
The licence file expires in set number of days or even months. Logging in after the file expires checks against the account and verifies its legitimacy. You might even consider generating a new licence file at this time.
There should be some smarts that give some leeway in the case that the users internet is down and the licence cannot be registered. Perhaps 7 days.
If the software is reinstalled on a new computer the user has to repeat the verification process.
As the others have stated there is no way to beat a determined pirate, since such a person will hack the code, but this should prevent or slow down casual piracy.
You can check out Microsoft's SLP - I haven't used it, but it definitely looks interesting (yknow, IF you're into MS stuff...)
One important point to note - no licensing mechanism will protect you from piracy, or even substantially reduce it. By definition, the licensing mechanism will be client-side - which is inherently breakable. Take a look at all what happened with DRM...
Your guideline should therefore be usability - the intent should be to use it as a general policy, the good guys will be comfortably limited to what they're supposed to be allowed to do, and the bad guys - well, the bad guys will get around your intent anyway, your best hope is to make it more work.
I'd be very wary of published software protection mechanisms, as they are much more likely to have published hacks. You are probably better off using some of the techniques to get a unique persistent ID and use this to roll your own protection mechanism. I also think that it is a poor idea to simple check the license whenever you run the program, as this leads the hacker to the location of your proection mechanism. IMO, your are better checking the license in a more random fashion, and more than once per session.
FWIW, I use hardware locks (hasp) for my high end desktop software, and device ID based licensing on mobile solutions. If you are selling small quantities of high cost software in a vertical market, IMHO, a good license protection mechanism makes sense, and hardware dongles work well. My experience has been that people will use more licenses than they purchase if this is not in place. For high volume, low cost software, I'd tend to live with the piracy based on increasing the size of the user base and product visibility.