Contents - Index


3.1 Key Features

  1. Machine Locking
  2. Comprehensive Licence Policy
  3. Portable Licence
  4. Network Licence
  5. Trial & Demo Licence
  6. Administration Tools
  7. Internet Software Registration

1. Machine Locking

Machine Locking ensures that an application will only execute on a PC or network against a valid licence. The licence cannot be copied to another machine nor can it be backed up and restored on the same machine. To achieve this, Sheriff employs an advanced proprietary algorithm for generating a unique 'fingerprint' of the machine where the licence database resides, as well as a unique "fingerprint" of the licence database itself.

2. Comprehensive Licence Policy

Sheriff offers the following licensing options:

  • Day Metering
  • Unit Metering
  • Expiration Control
  • Concurrency Control
  • Feature Access Control
  • Reusable Key

Day Metering enforces the lifespan of the application from the day of installation.

Unit Metering enables software publishers to decide what actions are chargeable and how they are charged.

Expiration Control forces an application to expire ('bomb out') on a specified date.

Concurrency limits the maximum number of concurrent users on a network. Sheriff treats many invocations of an application by the same user on the same computer as a single user.

Feature Access Control enables software publishers to categorise features in their products into many different levels and permits users to access only the levels that they have subscribed to.

Reusable Key enables a user to regenerate the licence database on the original machine without reference to the publisher in the event that the database file is damaged or overwritten. A Reusable Key is only issued when metering or expiration controls are not used.

3. Portable Licence

The portable licensing facility enables the user to export a licence from one machine to another, such as a portable PC (this facility can be disabled when issuing the licence key.

Normally, when a licence has been exported the protected application cannot execute on the original machine until the licence is re-imported, however the user can define the features of the exported licence within the terms of the original licence policy. So, for example, the exported licence may be set to expire after seven days and when it does the licence is automatically restored on the original machine.

4. Network Licence

Sheriff can be run on a network with a single licence database; typically this is installed on a file server. See Networking topic for further details.

5. Trial & Demo Licence

Typically, Sheriff-protected applications run in trial or demo mode if there is no valid licence present on the end user's machine. You can limit the number of days a trial is to last, specify a particular date when it will terminate or implement a demo version of your application with a limited feature set using feature access control. You can implement your trial application so that it is freely distributable but require a licence key once the trial period is over.

6. Administration Tools

Applications are provided for the vendor and end user:

  • Sheriff Licence Key Generator (SlsGen.exe)
  • Licence Administrator (SlsAdmin.exe).

The Licence Key Generator is used by software vendors to create keys for their customers and logs all the licence keys issued together with user information.

The Sheriff Licence Administrator enables end users to manage the licences of their Sheriff-protected applications, which may come from different publishers. The Licence Administrator can also be used to monitor licence usage on a network, such as who is logged on and what licence is being used, as well as the current state of licences, the renewal of licences and the import/export of licences.

Note that the full functionality of these applications is replicated in the Sheriff API (via SlsApi and SlsApiEx) enabling a very high degree of customisation.

7. Internet Software Registration

Sheriff ISR enables you to automate your licence key distribution via the Internet using Microsoft Internet Information Server (IIS).

In an Internet Software Registration system, three main functions that can be automated:

  1. Reference Code generation
  2. Licence Key generation
  3. Licence Key authorisation

For further details see topic Sheriff ISR