WO1999041651A2 - Method for protecting bytecode - Google Patents
Method for protecting bytecode Download PDFInfo
- Publication number
- WO1999041651A2 WO1999041651A2 PCT/SG1998/000010 SG9800010W WO9941651A2 WO 1999041651 A2 WO1999041651 A2 WO 1999041651A2 SG 9800010 W SG9800010 W SG 9800010W WO 9941651 A2 WO9941651 A2 WO 9941651A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- bytecode
- encrypted
- run
- accessing
- decryption key
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 33
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000001419 dependent effect Effects 0.000 description 2
- 235000010254 Jasminum officinale Nutrition 0.000 description 1
- 240000005385 Jasminum sambac Species 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
- G06F21/10—Protecting distributed programs or content, e.g. vending or licensing of copyrighted material ; Digital rights management [DRM]
- G06F21/12—Protecting executable software
- G06F21/121—Restricting unauthorised execution of programs
- G06F21/125—Restricting unauthorised execution of programs by manipulating the program code, e.g. source code, compiled code, interpreted code, machine code
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2211/00—Indexing scheme relating to details of data-processing equipment not covered by groups G06F3/00 - G06F13/00
- G06F2211/007—Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
Abstract
A method, software tool and system for protecting bytecode, which involves encrypting bytecode for an application, providing the encrypted bytecode to a user, executing a code loader to load the encrypted bytecode, access a decryption key, decrypt the encrypted bytecode, and pass the decrypted bytecode to a run-time system, and executing the decrypted bytecode with the run-time system.
Description
METHOD FOR PROTECTING BYTECODE
Field of the Invention
The present invention relates to a method for protecting compiled software application code, and a code protection system.
Background of Invention
There are many programming languages available that compile to platform independent bytecode, such as Elisp and Java, the latter being described in references A and B recited below. One of the greatest criticisms of such programming languages is that the bytecode, being defined at a high level, can easily be reverse- engineered into the source language. The problem is compounded with the wide availability of bytecode decompilers on the Internet, as described in reference C. It means that any novice computer user can produce readable source code from compiled bytecode. While the output of bytecode decompilers may not be the same as the original source code, it is nevertheless sufficiently close to allow any programmer to understand and make unauthorised use of the output.
The current most commonly used protection against bytecode decompilers is a bytecode obfuscator, as described in reference D. A bytecode obfuscator is a tool that goes through an application and renames all the symbolic information inside, such as the class names, method names and field names. Bytecode obfuscation does not protect the bytecode from being decompiled, but it makes the decompiled code a lot more difficult to understand.
Some bytecode obfuscators protect further by adding corrupted information into the application files to confuse the bytecode decompilers. This technique is frequently applied at the expense of violating the standard bytecode file format specification, which may render the resulting bytecode incompatible with certain implementations
of the run-time system. This technique is also limited, due to the availability of free tools on the Internet that can remove the corrupted information, as described in reference E.
Certain other techniques for protecting bytecode have been discussed in reference F. These other techniques, however, fall short in that they either require the main application logic to reside on a separate machine, or they require the developer not to use bytecode for sensitive application logic.
Summary of the Invention
In accordance with the present invention there is provided a method of protecting bytecode, including: encrypting bytecode for an application; providing the encrypted bytecode to a user; executing a code loader to load the encrypted bytecode, access a decryption key, decrypt the encrypted bytecode, and pass the decrypted bytecode to a run-time system; and executing said decrypted bytecode with said run-time system.
The present invention also provides a software tool stored on a computer readable storage medium, including: means for accessing bytecode; means for determining if the bytecode is encrypted; means for accessing a decryption key; means for decrypting encrypted bytecode using the decryption key; and means for passing bytecode to a run-time system.
The present invention further provides a software protection system, including: means for accessing bytecode; means for determining if the bytecode is encrypted;
means for accessing a decryption key; means for decrypting encrypted bytecode using the decryption key; and means for passing bytecode to a run-time system.
The present invention also provides a method for execution by a computer system, including: accessing bytecode; determining if the bytecode is encrypted; accessing a decryption key; decrypting encrypted bytecode using the decryption key; and passing bytecode to a run-time system.
Brief Description of the Drawing
A preferred embodiment of the present invention is hereinafter described, by way of example only, with reference to the accompanying drawing, wherein:
Figure 1 is a flow diagram of a process executed by a code loader of the preferred embodiment.
Detailed Description of the Preferred Embodiment
A software protection system of the preferred embodiment uses a software tool, hereinafter referred to as deCaf™, which includes an encryption module, a code loader and a driver program. The system comprises at least one computer having electronic memory used for storing, reading and executing the software tool, and a run-time system for executing bytecode of a software application. The system normally comprises a server computer and a user computer, where the tool is stored on the server with application bytecode, and the bytecode when encrypted is transmitted to the user's computer with the code loader and the driver program for storage and execution on the user's computer. The code loader and the drive program can be transmitted separately and also can be prestored on a user's computer. The
encryption module is used to encrypt bytecode, which can then only be decrypted by the code loader. The driver program installs the code loader for a run-time system of a user's machine, instructs the code loader to decrypt the encrypted bytecode, and then causes the decrypted code to be executed on the user's machine. By applying encryption to bytecode, deCaf ™ is able to prevent bytecode decompilers from reading the bytecode. The decompilers are unable to decompile the encrypted bytecode without first decrypting it. To understand the encrypted bytecode format, normally this will require modification of a run-time system, but deCaf™ does not require any such modification, as it is able to rely on the code loader which can be applied in any run- time system that supports the installation of a code loader by the software application to be executed. In particular, deCaf™ is able to encrypt Java software applications and then execute them on an unmodified Java run-time system, being the Java Virtual Machine.
The encryption module when executed, normally by a transmitting server, acts on the compiled bytecode of a software application and applies an encryption algorithm to produce decrypted bytecode. Any secured encryption algorithm can be used, although one which enhances the execution speed of the encryption module is preferred.
In any encryption algorithm, there is an encryption key as well as a decryption key. In an asymmetric encryption algorithm, the encryption and decryption keys are different. While in a symmetric encryption algorithm, both keys are the same. Regardless of which is used, the decryption key is distributed to the application user so the encrypted bytecode can be decrypted later and executed.
This key distribution is done in one of the following ways:
1. Using a trusted public-private key authentication infrastructure. In the presence of a trusted public-private key authentication infrastructure, the user's public key is used to encrypt the application bytecode. Then, the private key can decrypt the bytecode on receipt. As such, no one else other than a legitimate
user can run the software. No actual key distribution is required since the user uses his own private key for decryption of the software.
2. Embedding the decryption key in the encrypted bytecode. In the event that an infrastructure to support key distribution is not available, the decryption key can be hidden within the encrypted bytecode. The code loader will know this hidden location, so that the key can be extracted at run-time to decrypt the bytecode. To avoid disclosing the secret location of the key within the encrypted bytecode, the location can be made random by having it dependent on a relatively random data pattern, such as the message digest of the application code. The customised code loader will normally be provided together with the encrypted bytecode. As such, this method of distributing the decryption key is not completely secure, since a hacker could go through the code of the code loader to try and determine the location of the decryption key. Nevertheless, the task of doing so is labourious enough to deter most hackers. Thus this key distribution method is still useful when protecting less sensitive application bytecode.
3. Distributing the decryption key separately. Instead of embedding the decryption key within the encrypted application, the decryption key is passed separately to the user. The encrypted application bytecode is distributed to the user who is then required to register his particulars before the decryption key is passed. This key distribution method has the same weakness as the former, in that a hacker could go through the labourious task of attempting to understand the code loader, and determine how it applies the decryption key. As such, its usefulness is also confined to protecting less sensitive application bytecode. However, this method helps keep track of legitimate users, much like the serial number required to install most commercial software. If an illegal copy of encrypted software is received, it can be traced back to its original legitimate user.
In some run-time environments, such as Java's, application software running in the environment is given the ability to install its own code loader. A code loader (known as the ClassLoader in Java) is a small piece of software that is responsible for loading the application code from a disk, a network or any other storage medium. DeCaf™ exploits this feature by providing it's own code loader to perform code decryption at run-time, hence omitting the need to modify the run-time system.
The code loader's role is to find and load the correct application bytecode, and then pass it to the run-time system. To provide a code loader that can understand the encrypted bytecode, appropriate decryption routines are inserted and executed between the loading of the application code and handing it over to the run-time system. This ensures that the run-time system always receives bytecode it can execute.
The code loader of deCaf™, as shown in Figure 1 , first receives a request to load a bytecode file, at step 2. When the run-time system needs to load a bytecode file, it passes the request to the code loader for execution. The code loader then looks for the bytecode file, at step 4. The bytecode file can reside anywhere in the local disk, or even in a network. In most run-time systems, the list of places to look for the bytecode is given by a predefined variable which the user can change. In Java, this is given by the CLASS PATH environment variable. Once the application bytecode file is loaded, the custom code loader determines whether it is in encrypted form, at step 6. In deCaf™ a predefined constant of OxDECAFO is assigned to all encrypted bytecode. The loader determines the existence of this constant in order to decide whether the bytecode is encrypted or not. If the loader determines that the bytecode is encrypted, operation proceeds to step 8, whereas otherwise operation proceeds to step 12. At step 8, the code loader loads the decryption key. Loading the decryption key will depend on how the decryption key is distributed. In a current implementation of deCaf™, the decryption key is encoded in the encrypted bytecode. The loader accesses this information, and loads the decryption key accordingly. Once the decryption key is loaded, the custom code loader executes the required decryption
algorithm on the encrypted code, at step 10. As mentioned earlier, any secure encryption algorithm can be chosen. One particular encryption algorithm can be chosen, or the type of encryption algorithm used can be encoded in the encrypted bytecode. In the latter case, the code loader looks up the type of encryption algorithm used, and applies the corresponding decryption algorithm. Once the bytecode has been decrypted, or if it is not encrypted in the first place, it is passed directly to the run-time system, at step 12 by the code loader.
The driver program of deCaf ™ is used to tie the components of the tool together and run the encrypted application. The driver program executes the following steps:
1. Install the code loader in the run-time system;
2. Instruct the code loader to load the encrypted application bytecode; and
3. Run the decrypted application.
All the above tasks are dependent on the run-time system to be used. To install the code loader in Java, a code loader object of deCaf™ is initiated. This is followed by extracting out the encrypted application bytecode, and passing it to the loadClass procedure of the code loader. Finally, the Java reflection API is used to invoke the main procedure of the decrypted application.
Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention as herein described with reference to the accompanying drawing.
References
A. James Gosling, Bill Joy, Guy Steele, The Java Language Specification, ISBN: 0-201- 63451-1 , Addison Wesley.
B. Tim Lindholm, Frank Yellin, The Java Virtual Machine Specification, ISBN: 0-201-63452- X, Addison Wesley.
C. Decompilers available on the Internet: - Mocha, http://www.brouhahn.com/~eric/computers/mocha.html
WingDis, http://www.winqsoft.com/windis.shtml
Jasmine, http://www.members.tripod.com/~SourceTec/
DejaVu, http://ww.isq.de/OEW/Java
Jad, http://web.unicom.com.cv/~kpd/iad.html
D. Qusay H. Mahmoud, Protect your bytecodes from reverse engineering/decompilation. In Java World, http://www.iavaworld.com/iavatips/iw~iavatip221.html.
E. Unobfuscator example: Zelix KlassMaster, http://www.zelix.com/klassmaster/index.html.
F. Scott Oaks. Protecting your bytecode. In Java Report, pgs. 86-88, November 1997.
Claims
1. A method of protecting bytecode, including: encrypting bytecode for an application; providing the encrypted bytecode to a user; executing a code loader to load the encrypted bytecode, access a decryption key, decrypt the encrypted bytecode, and pass the decrypted bytecode to a run-time system; and executing said decrypted bytecode with said run-time system.
2. A method as claimed in claim 1 , wherein the decryption key is encoded in the encrypted bytecode.
3. A method as claimed in claim 1 , wherein the decryption key is a private key of a user.
4. A method as claimed in claim 1 , including registering particulars of the user to obtain said decryption key.
5. A method as claimed in claim 1 , including executing a driver program to install the code loader for the run-time system, and cause the code loader to access the encrypted bytecode.
6. A method as claimed in claim 5, including providing the code loader and driver program with the encrypted bytecode.
7. A method as claimed in claim 1 , including providing the code loader with the encrypted bytecode.
8. A method as claimed in claim 6 or 7, wherein said providing step comprises transmitting from a network computer to a computer of the user.
9. A software tool stored on a computer readable storage medium, including: means for accessing bytecode; means for determining if the bytecode is encrypted; means for accessing a decryption key; 5 means for decrypting encrypted bytecode using the decryption key; and means for passing bytecode to a run-time system.
10. A software tool as claimed in claim 9, wherein the determining means relies on predetermined data stored in encrypted bytecode.
10
11. A software tool as claimed in claim 9, wherein the key accessing means accesses data to determine the storage location of the decryption key.
12. A software tool as claimed in claim 11, wherein the key accessing means 15 accesses data to determine the decryption algorithm to be used by the decrypting means.
13. A software tool as claimed in any one of claims 9 to 12, wherein a code loader comprises all of said means, and the tool further includes:
20 means for installing the code loader in the run-time system; means for causing the code loader to access the bytecode; and means for causing execution of the bytecode when passed to the run-time system.
25 14. A software tool as claimed in claim 12, including means for encrypting bytecode.
15. A software protection system, including: means for accessing bytecode; 30 means for determining if the bytecode is encrypted; means for accessing a decryption key; means for decrypting encrypted bytecode using the decryption key; and means for passing bytecode to a run-time system.
16. A software protection system as claimed in claim 15, wherein the determining 5 means relies on predetermined data stored in encrypted bytecode.
17. A software protection system as claimed in claim 15, wherein the key accessing means accesses data to determine the storage location of the decryption key.
10 18. A software protection system as claimed in claim 17, wherein the key accessing means accesses data to determine the decryption algorithm to be used by the decrypting means.
19. A software protection system as claimed in any one of claims 15 to 18, wherein 15 a code loader comprises all of said means, and the system further includes: means for installing the code loader in the run-time system; means for causing the code loader to access the bytecode; and means for causing execution of the bytecode when passed to the run-time system. 0
20. A software protection system as claimed in claim 19, including means for encrypting bytecode.
21. A method for execution by a computer system, including: 5 accessing bytecode; determining if the bytecode is encrypted; accessing a decryption key; decrypting encrypted bytecode using the decryption key; and passing bytecode to a run-time system. 0
22. A method as claimed in claim 21 , wherein the determining step is executed by searching for predetermined data stored in encrypted bytecode.
23. A method as claimed in claim 21 , wherein the key accessing step includes accessing data to determine the storage location of the decryption key.
5
24. A method as claimed in claim 23, wherein the key accessing step includes accessing data to determine the decryption algorithm to be used by the decrypting means.
10 25. A method as claimed in any one of claims 21 to 24, wherein a code loader executes the accessing, determining, decrypting and passing steps, and the method further includes: installing the code loader for the run-time system; causing the code loader to access the bytecode; and 15 causing execution of the bytecode when passed to the run-time system.
26. A method as claimed in claim 25, including encrypting bytecode.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU66453/98A AU6645398A (en) | 1998-02-13 | 1998-02-13 | Method for protecting bytecode |
| GB0009367A GB2349250A (en) | 1998-02-13 | 1998-02-13 | Method for protecting bytecode |
| PCT/SG1998/000010 WO1999041651A2 (en) | 1998-02-13 | 1998-02-13 | Method for protecting bytecode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/SG1998/000010 WO1999041651A2 (en) | 1998-02-13 | 1998-02-13 | Method for protecting bytecode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO1999041651A2 true WO1999041651A2 (en) | 1999-08-19 |
| WO1999041651A3 WO1999041651A3 (en) | 2002-06-20 |
Family
ID=20429836
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/SG1998/000010 WO1999041651A2 (en) | 1998-02-13 | 1998-02-13 | Method for protecting bytecode |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU6645398A (en) |
| GB (1) | GB2349250A (en) |
| WO (1) | WO1999041651A2 (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002031648A2 (en) | 2000-10-11 | 2002-04-18 | Sealedmedia Limited | Methods of providing java tamperproofing |
| WO2002071195A1 (en) * | 2001-02-05 | 2002-09-12 | Hmd-Software Ag | Method and device for transmitting programme codes via the internet |
| GB2343022B (en) * | 1998-10-19 | 2003-01-08 | Ibm | Encrypting of java methods |
| US6681212B1 (en) | 1999-04-23 | 2004-01-20 | Nianning Zeng | Internet-based automated system and a method for software copyright protection and sales |
| WO2004098121A2 (en) * | 2003-05-02 | 2004-11-11 | Bitarts Limited | Delivering a software component |
| WO2006063876A1 (en) * | 2004-12-17 | 2006-06-22 | Siemens Aktiengesellschaft | Method and device for encoding and for carrying out a software library |
| CN101957903A (en) * | 2010-09-13 | 2011-01-26 | 中兴通讯股份有限公司 | Method and device for protecting class files |
| EP3188063A1 (en) * | 2015-12-29 | 2017-07-05 | GuardSquare NV | A build system |
| CN111131281A (en) * | 2019-12-30 | 2020-05-08 | 北京永新视博数字电视技术有限公司 | Message transmission method, device and system and protection code updating method and device thereof |
| US11550883B2 (en) | 2020-09-08 | 2023-01-10 | Assured Information Security, Inc. | Code protection |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2385951A (en) | 2001-09-21 | 2003-09-03 | Sun Microsystems Inc | Data encryption and decryption |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0115395A2 (en) * | 1983-01-26 | 1984-08-08 | International Computers Limited | Computer processor system with software protection |
| US4562305A (en) * | 1982-12-22 | 1985-12-31 | International Business Machines Corporation | Software cryptographic apparatus and method |
| US4740890A (en) * | 1983-12-22 | 1988-04-26 | Software Concepts, Inc. | Software protection system with trial period usage code and unlimited use unlocking code both recorded on program storage media |
| EP0359220A2 (en) * | 1988-09-16 | 1990-03-21 | Wayne W. Chou | Method and apparatus for protecting computer software utilizing coded filter network in conjunction with an active coded hardware device |
| EP0515739A1 (en) * | 1991-05-31 | 1992-12-02 | International Business Machines Corporation | Program code generator |
| EP0555715A1 (en) * | 1992-02-12 | 1993-08-18 | International Business Machines Corporation | User defined cryptographic function facility |
| US5259029A (en) * | 1990-05-16 | 1993-11-02 | Duncan Jr F Jeff | Decoding device for computer software protection |
| US5522073A (en) * | 1993-11-22 | 1996-05-28 | Hewlett-Packard Company | Method and apparatus for automating and controlling execution of software tools and tool sets via when/then relationships |
| US5544244A (en) * | 1993-10-28 | 1996-08-06 | Nec Corporation | Method for protecting an enciphered computer object code against cryptanalysis |
| EP0740250A2 (en) * | 1995-04-24 | 1996-10-30 | Motorola, Inc. | Apparatus for dynamically reading and writing multiple object code formats through use of objective code readers and writers |
| US5604803A (en) * | 1994-06-03 | 1997-02-18 | Sun Microsystems, Inc. | Method and apparatus for secure remote authentication in a public network |
-
1998
- 1998-02-13 GB GB0009367A patent/GB2349250A/en not_active Withdrawn
- 1998-02-13 WO PCT/SG1998/000010 patent/WO1999041651A2/en active Application Filing
- 1998-02-13 AU AU66453/98A patent/AU6645398A/en not_active Abandoned
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4562305A (en) * | 1982-12-22 | 1985-12-31 | International Business Machines Corporation | Software cryptographic apparatus and method |
| EP0115395A2 (en) * | 1983-01-26 | 1984-08-08 | International Computers Limited | Computer processor system with software protection |
| US4740890A (en) * | 1983-12-22 | 1988-04-26 | Software Concepts, Inc. | Software protection system with trial period usage code and unlimited use unlocking code both recorded on program storage media |
| EP0359220A2 (en) * | 1988-09-16 | 1990-03-21 | Wayne W. Chou | Method and apparatus for protecting computer software utilizing coded filter network in conjunction with an active coded hardware device |
| US5259029A (en) * | 1990-05-16 | 1993-11-02 | Duncan Jr F Jeff | Decoding device for computer software protection |
| EP0515739A1 (en) * | 1991-05-31 | 1992-12-02 | International Business Machines Corporation | Program code generator |
| EP0555715A1 (en) * | 1992-02-12 | 1993-08-18 | International Business Machines Corporation | User defined cryptographic function facility |
| US5544244A (en) * | 1993-10-28 | 1996-08-06 | Nec Corporation | Method for protecting an enciphered computer object code against cryptanalysis |
| US5522073A (en) * | 1993-11-22 | 1996-05-28 | Hewlett-Packard Company | Method and apparatus for automating and controlling execution of software tools and tool sets via when/then relationships |
| US5604803A (en) * | 1994-06-03 | 1997-02-18 | Sun Microsystems, Inc. | Method and apparatus for secure remote authentication in a public network |
| EP0740250A2 (en) * | 1995-04-24 | 1996-10-30 | Motorola, Inc. | Apparatus for dynamically reading and writing multiple object code formats through use of objective code readers and writers |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2343022B (en) * | 1998-10-19 | 2003-01-08 | Ibm | Encrypting of java methods |
| US6681212B1 (en) | 1999-04-23 | 2004-01-20 | Nianning Zeng | Internet-based automated system and a method for software copyright protection and sales |
| EP2362324A3 (en) * | 2000-10-11 | 2011-10-05 | Sealedmedia Limited | Methods of providing java tamperproofing |
| WO2002031648A2 (en) | 2000-10-11 | 2002-04-18 | Sealedmedia Limited | Methods of providing java tamperproofing |
| EP1325411B1 (en) * | 2000-10-11 | 2018-03-07 | Oracle Corporation UK Limited | Methods of providing java tamperproofing |
| WO2002071195A1 (en) * | 2001-02-05 | 2002-09-12 | Hmd-Software Ag | Method and device for transmitting programme codes via the internet |
| WO2004098121A2 (en) * | 2003-05-02 | 2004-11-11 | Bitarts Limited | Delivering a software component |
| WO2004098121A3 (en) * | 2003-05-02 | 2004-12-29 | Bitarts Ltd | Delivering a software component |
| WO2006063876A1 (en) * | 2004-12-17 | 2006-06-22 | Siemens Aktiengesellschaft | Method and device for encoding and for carrying out a software library |
| CN101957903A (en) * | 2010-09-13 | 2011-01-26 | 中兴通讯股份有限公司 | Method and device for protecting class files |
| EP3188063A1 (en) * | 2015-12-29 | 2017-07-05 | GuardSquare NV | A build system |
| WO2017114931A1 (en) * | 2015-12-29 | 2017-07-06 | Guardsquare Nv | A build system with plugins for encryption of application components |
| US10713339B2 (en) | 2015-12-29 | 2020-07-14 | Guardsquare Nv | Build system with plugins for encryption of application components |
| CN111131281A (en) * | 2019-12-30 | 2020-05-08 | 北京永新视博数字电视技术有限公司 | Message transmission method, device and system and protection code updating method and device thereof |
| US11550883B2 (en) | 2020-09-08 | 2023-01-10 | Assured Information Security, Inc. | Code protection |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2349250A (en) | 2000-10-25 |
| WO1999041651A3 (en) | 2002-06-20 |
| GB0009367D0 (en) | 2000-05-31 |
| AU6645398A (en) | 1999-08-30 |
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