Category: Announcements

Cryptolens joins Stripe partner program

Most people today don’t know that only three percent of GDP is online. That’s why we’re
excited to join the Stripe Partner Program to increase internet commerce and help
companies start, run, and scale their businesses.

By joining the program, our mutual customers will now benefit from the combination of
Cryptolens secure licensing platform with Stripe’s seamless payments platform.

We believe that removing barriers to online commerce helps more new businesses get
started, levels the playing field, and increases economic output and trade around the
world. Together with Stripe, our mission is to bring more commerce online and increase
the GDP of the internet.

Recurring Payments with Stripe combined with Software Licensing

A popular licensing model amongst software vendors is subscription-based licensing. It is generally seen as a smaller risk for the customer than traditional one-time payments (eg. which normally require a large commitment), but at the same time it provides recurring revenues for the software vendor.

You can get started with recurring payments by visit our help pages.


Recurring payments are implemented as a part of the customer portal. Thanks to this update, customers can not only manage their existing licenses but also subscribe for new ones.

Everything related to payments, plans and subscriptions is managed by Stripe, so if you’re already using Stripe, it’s quite easy to get started with the new recurring payments feature. If you do not have Stripe, it’s quite easy to get started. A tutorial can be found here.

In addition to recurring payments, the customer portal makes it possible to use user account authentication, described in the previous article.


Example when the customer has subscribed to a new plan:

The new license will show up on the home page of the customer:

Reviewing a license key and the subscription it is associated with:

Software licensing for PHP applications

We recently added support for key verification in PHP, available on GitHub. Below is the sample code that can be included into your application.


$activate = cryptolens_activate(
      // Access token
      // Product Id
    , 3646
      // License Key
      // Machine code
    , '289jf2afs3'

// $activate is now a boolean indicating if the activation attempt was successful or not


The repository contains all the necessary information to get the code to work (eg.. finding access tokens)

Usage-based (pay per use) software licensing in .NET

Many software vendors nowadays move away from one-time payments to other licensing models. One such example is the usage-based model. By doing so helps lowering the barrier of entry for new customers, as they no longer need to commit to the product long term, which is usually the case with one-time payments. If you already have a subscription model, supporting usage-based payments can help you to monetise a group of users who would otherwise not buy the product.

You can read the entire tutorial here.

Getting started

In Cryptolens, usage-based licensing can be implemented using data objects, aka custom variables. We can use these variables to record how often features are used and keep track of any usage credits that a customer has purchased. There are two ways of billing customers:

  • Upfront payment: customers need to purchase usage credits in advance.
  • Based on actual usage: customers pay for the actual usage in the end of the billing period.

Charging based on actual usage

If you choose to charge your customers based on actual usage, we can simply use the code below:

var auth = "Access token with AddDataObject, ListDataObject and IncrementIntValue permission. Please also set KeyLock value to '-1'";
var licenseKey = "LZKZU-MPJEW-TARNP-UHDBQ";

var result = Data.ListDataObjects(auth, new ListDataObjectsToKeyModel 
    Contains = "usagecount",
    Key = licenseKey,
    ProductId = 3349 

var obj = result.DataObjects.Get("usagecount");

if (obj == null)
    // make sure to create it in case it does not exist.
    Data.AddDataObject(auth, new AddDataObjectToKeyModel { Key = licenseKey, ProductId = 3349, Name = "usagecount", IntValue = 1 });

    if(res == null || res.Result == ResultType.Error)
        Console.WriteLine("Could not create new data object. Terminate." + res.Message);
    var res = obj.IncrementIntValue(auth, 1, licenseKey: new LicenseKey { Key = licenseKey, ProductId = 3349 });

    if (res == false) 
        Console.WriteLine("We could not update the data object. Terminate.");

Upfront payments

If you instead want to charge your users upfront, we need to create the data objects when creating the license. If you are using payment forms, we can set up two requests, one creating a new license and another creating a new data object (inspired by this tutorial), as the result from key creation will be “piped” into data object creation request. You can then have another payment form that allows users to refill their credits, in which case the custom field can be used.

You can use the code below to verify if the limit was reached inside your application:

var auth = "Access token with AddDataObject, ListDataObject and IncrementIntValue permission. Please also set KeyLock value to '-1'";
var licenseKey = "LZKZU-MPJEW-TARNP-UHDBQ";

var result = Data.ListDataObjects(auth, new ListDataObjectsToKeyModel { Contains = "usagecount", Key = licenseKey, ProductId = 3349 });
var obj = result.DataObjects.Get("usagecount");

var res = obj.DecrementIntValue(auth, decrementValue: 1, enableBound:true, lowerBound: 0, licenseKey: new LicenseKey { Key = licenseKey, ProductId = 3349 });

if (!res)
    Console.WriteLine("Could not decrement the data object. The limit was reached.");

Sending news and update notifications using Messaging API

The new Messaging API allows you to easily send notifications to some or all of your end users. For example, it can help you to notify customers running an older version of your application to upgrade as well as keep them updated about the latest news.

Getting Started

It’s quite simple to get started with the Messaging API. The dashboard is available here, which is where you can send the messages. In order receive them in your own app, you can use the GetMessages method. One thing to keep in mind are the two optional parameter, time and channel. These allow you to tell Cryptolens which messages you want to receive. Time is used as a reference when the last message was seen and channel is a way to group those messages. If these are not specified, all of the messages will be returned.

For example, let’s say you want to implement updates notifications. In that case, we can use the code below to ensure that only older versions of the software receive the message. The version itself is specified as a unix timestamp in the currentVersion parameter, which should be the time when you published the release.

var currentVersion = 1538610060;
var result = (GetMessagesResult)Message.GetMessages("token with GetMessages permission", new GetMessagesModel { Channel = "stable", Time = currentVersion } );

if(result == null || result.Result == ResultType.Error)
    // we could not check for updates
    Console.WriteLine("Sorry, we could not check for updates.");
else if (result.Messages.Count > 0)
    // there are some new messages, we pick the newest one 
    // (they are sorted in descending order)
    // No messages, so they have the latest version.
    Console.WriteLine("You have the latest version.");


You can see the entire tutorial about updates notifications for more details. There is also about notifications.

Computing and verifying VAT in .NET (for EU businesses)

When you sell your software as an EU business, you need to take into account the VAT, which depends on whether you sell to a private individual or a company, and their country of residence. Moreover, you need to ensure that the VAT id that they have provided is correct.

In order to solve these two problems, we have published a library for .NET, available as a NuGet package (with source code on GitHub).


The library has two methods, CalculateVAT and IsValidVAT, which are quite simple to use. We explain their purpose below:

  • CalculateVATThis method asks for the country of residence of the individual or the company, and their VAT id (if applicable). Based on this information, it will calculate the necessary tax that should be applied to the order. Note, we assume you sell products or services that are covered by the standard VAT (i.e. some categories such as books have a lower tax in some countries).
  • IsValidVATThis method is responsible for VAT id verification. We use the European Commission’s API for that. Note, this API is not up 24/7 and can be unresponsive some times. You can view all the times it is down (given the country of residence) here.

New AI feature helps optimize software pricing

Setting the price for a product you intend to sell is hard, especially when pricing usually changes over time. Cryptolens’ new AI feature helps software providers set the price by analyzing how each individual user uses their software.

Problem with existing pricing models

It is often challenging for software providers to price their product optimally.

A good example that demonstrates this is when you set the price for accounting software. Imagine you have two groups of customers: those that use the software regularly in their profession (eg. accountants helping other companies) and those that only use it once a month (eg. small businesses). It makes sense to have different pricing models for these two groups: professionals can be charged monthly (and are very likely to pay more) and the smaller business can pay per usage (eg. per generated monthly report).

As a result, software providers are able to increase their revenues and capture both customer groups by taking into account the true value the software has for each group, and adjusting the pricing model to meet the needs for each group.

How Cryptolens’ new AI feature optimizes revenue

Cryptolens’ new AI feature analyzes the usage information generated by each user (and the history from previous users) and determines the value a product (and its features) has for each user, and then helps to determine the best pricing model for that particular user or user group.

For example, if the value of the features is higher than the price of the product, it would be reasonable to increase the price. If, however, only a subset of the product’s features are used, a new product based on a subset of the features offered at a lower price could be a solution (or potentially suggest an alternative licensing model such as usage-based model).

The goal is to provide insights on the value of a product and its features for each user, and assist in creating new product offerings with more optimal pricing.

Getting started

In order to benefit from our AI analysis, the following is required:

First, you need to register each time a customer interacts with a certain feature of the product (if you have a licenseKey object, you can call the new RegisterEvent method). For example, when they start the salary module (if it’s an accounting software), you can send FeatureName=”SalaryModule” and EventName=”start”. If they generate a report, you can keep the feature name, but change the event name to “report_generated”.

The second step is to register successful transactions (eg. when the customer buys the software). In that case, you can still call RegisterEvent method, and include the value and currency parameters.

Please get in touch with us if you need any help setting this up. We are currently looking for beta testers and would be happy if you can participate. You can reach out to us at

Once enough data is collected, you will be able to see it in the analytics dashboard.

Floating licenses supported out of the box

Floating licenses allow your customers to use a license on a limited number of machines simultaneously. For example, they can have your software installed on 100 computers, but only be able to use it on 20 of them at once.

This is similar to node-locked licenses (aka machine code locking) that is part of the Cryptolens for quite some time, with the exception that a license does not have to be deactivated when they are to be used on a new device.

Note: floating licenses are supported since v405 of Cryptolens.Licensing library for .NET. Support for C++ is coming soon.


Cryptolens Licensing for .NET (new package)

You might have noticed that we have changed from being called Serial Key Manager to Cryptolens. As a result, the design language, domains and naming of our products has changed. Now, we are also updating the .NET packages that are used to interact with the Web API. We will describe the changes below (you can also see the release notes)

New package

The new package, Cryptolens.Licensing, is essentially the same as SKGLExtension, with several improvements described below. You can either install it using NuGet or download pre-compiled binaries for the desired framework. Read more here.

.NET Standard

The new library introduces support for .NET Standard 2.0, which means more platforms in the .NET family can use it (eg. .NET Core 2.0). You can see all the supported platforms here. There is still support for .NET Framework 4.0, although most of the new features will be in the .NET Framework 4.6.

License verification on the server

Previously, most of the license validation logic was performed on the client, eg. you had to check expiration, features in the client code. The new Cryptolens client now supports the ability to create rules and perform these checks on the server. The rules are set up using feature definitions on the product page. You only need to set Metadata=True, which will give you access to the license key status. A code example is shown below (this will automatically check that the key has not expired and that it’s not blocked).

var result = Key.Activate(activateToken, new ActivateModel() 
    Key = "license",
    ProductId = 3349, 
    Sign = true, 

    Console.WriteLine("License is valid!")

A good practise is to verify the signature of this license status object, which can be done with VerifySignature. At the moment, this requires .NET Framework 4.6 or .NET Standard 2.0 to work.