.NET Encryption Library

$ 99.95

Easily secure credit cards, social security numbers, passwords and other sensitive information.  Trusted by Sony and other major corporations.

Visual Studio Magazine 2007 Readers Choice Merit Award


"I was looking for a .NET library I could use for projects I was working on involving encryption. I needed to quickly develop proof-of-concept utilities and I found the Kellerman encryption library to be the most complete at any price. I especially like the ease of which the library can be implemented; I was up and running minutes after downloading the product. Thanks for the excellent work."

Chris Steele

When you need to encrypt sensitive personal information such as credit cards, social security numbers, and passwords; look no further than the .NET Encryption Library by Kellerman Software. The .NET Encryption Library supports the strongest encryption algorithms and key sizes currently available. It also has public and private key encryption with RSA. It supports all .NET project types including .NET Standard, ASP.NET Core, ASP.NET MVC, WPF, Webforms, Winforms, WCF, Windows Services, and Web Services. It can be used with any .NET language including VB.NET and C#. Download the full list of features.

While it can be purchased separately, this product is also included in the Gold Suite. Gold Suite subscribers receive all product updates and all new products as part of a yearly subscription. It is the best value in the industry.


Feature Description
Symmetric Encryption Supports these powerful encryption algorithms: Rijndael, Twofish, Blowfish, DES, TripleDES, ChaCha20, RC4, Idea, XTEA, and RC2. Initialization vectors and salts are supported.
Asymmetric Encryption Public/Private Key X509 Certificate or RSA encryption is supported. The libary also validates X509 certificate signing. ECDH (Elliptical Curve Diffie Hellman) shared secret encryption is supported.
Hashing Numerous hashing algorithms are supported including Grindal256, Grindal512, RadioGatun32, RadioGatun64, GHash, Ripemd160, SKEIN, Blake, Keccak, Elf, SumBSD, SHA1, SHA256, SHA384, SHA512, MD2, MD4, MD5, FCS16, FCS32, HAVAL, Ripemd320, Whirlpool, Tiger, Gost Hash, hmac-sha2-256, hmac-sha2-256-96, hmac-sha2-384, hmac-sha2-512, hmac-sha2-512-96, hmac-sha1-96, and hmac-md5-96.
Compression Compression of bytes, streams and files with GZip, Deflate, or MiniLZO is supported.
Secure Erase Secure erase files and directories for maximum security after you have encrypted your files. Supports these overwrite algorithims, null, random, Department of Defense 5220.22-M, Department of Defense DoD 5220.22-M ECE, Gutmann, US Navy NAVSO P-5239-26, Schneier, German VSITR, US Army AR 380-19, Russian GOST R 50739-95 Version 2, and US Air Force AFSSI-5020.
Binary Encoding These encoding mechanisms are supported: uuEncode, Quoted Printable, Base32, Base58, Base58 with Checksum, Base64 and Hex String.
Format Preserving Encryption Plain text after it is encrypted will be in a printable range of characters having the same length as the original plain text.
One Time Password Generate a numeric password that is password that is good for the specified number of seconds.
Easy to Use The library has methods to encrypt/decrypt strings, bytes, streams and files. Strings are automatically Base64 encoded for use in storage in the text field of a database or embedding in XML.
Documentation Industry standard formatted help and an easy to use demo is included.
100% Managed Code 100% managed code written in C#. No external dependencies or libraries are required except for the .NET Framework 4.5 and higher OR .NET Standard 2.0 and higher, or .NET Core 2.0 and higher
Royalty Free Distribution Include with any .NET project royalty free.
1 Year Free Upgrades Purchase today and all upgrades are free for the next year.
60 Day Money Back Guarantee At Kellerman Software, we want you to be totally satisfied with your purchase. Receive a refund within 60 days when ordering from KellermanSoftware.com. Source code versions are non-refundable due to their nature.
Lifetime Support Lifetime E-mail technical support is included.

How does the .NET Encryption Library stack up against the competition?

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Download a free 30 day trial today.

  • Full working version
  • Includes technical support
  • Works with .NET 4.5 and higher, .NET Standard 2.0 and higher, OR .NET Core 2.0 and higher

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"Howard Day & Associates uses the Kellerman Encryption Library as part of our suite of offerings for mobile telephone companies. Our company previously licensed Kellerman’s email verification product. We’ve found the software to be stable and the example code to be well documented and most helpful for our development efforts.

Kellerman ranks in the top 1% of software vendors we deal with for software quality, example code thoroughness, and product performance. When we’ve had questions they have been very prompt in responding.

Jeffrey Howard


Howard Day & Associates Inc.

When using this encryption software you meet the following system requirements.

  • Windows 98, Windows 98 SE, Windows 2000 with SP4, Windows ME, Windows XP with SP2, Windows 7, Windows 8, Windows 10, Windows 2000 Server with SP4, Windows Server 2003, Windows Server 2008, Windows Server 2012, or Windows Server 2016
  • Works with .NET 4.5 and higher, .NET Standard 2.0 and higher, OR .NET Core 2.0 and higher
Using the Kellerman .NET Encryption Library is easy. Instantiate the object and call a method.
//Instantiate the Kellerman Encryption Library
Encryption oEncrypt = new Encryption();

//Encrypt/Decrypt a Visa Credit Card Number
string encryptedString = oEncrypt.EncryptString(EncryptionProvider.Rijndael, "MyPasswordKey" , "4012888818888");
string decryptedString = oEncrypt.DecryptString(EncryptionProvider.Rijndael, "MyPasswordKey" , encryptedString);

//Encrypt/Decrypt a file
oEncrypt.EncryptFile(EncryptionProvider.Rijndael, "MyPasswordKey" , "c:\\testfile.txt" , "c:\\encrypted.txt");
oEncrypt.DecryptFile(EncryptionProvider.Rijndael, "MyPasswordKey" , "c:\\encrypted.txt" , "c:\\decrypted.txt");

//One Way Hash a password 
oEncrypt.HashString(HashProvider.HAVAL, "SecretPassword");

//Compress/Decompress a File
oEncrypt.CompressFile(CompressionType.GZip, "c:\\testfile.txt" , "c:\\testfile.gz");
oEncrypt.DecompressFile(CompressionType.GZip, "c:\\testfile.gz" , "c:\\decompressed.txt");

//Secure erase a file

Q: How do I use my license key?
A: Encryption oEncrypt = new Encryption("my user name","my license key");

Q: I lost my license key how do I retrieve it?
A: Go to your account

Q: I lost my software how do I retrieve it?
A: Go to downloads

Q: Where can I download the latest version of my software?
A: Click the download tab.

Q: How does the licensing work?
A: Each developer that uses the encryption library must have a license. You may distribute your application to end users royalty free or use it on an unlimited number of servers. A site license is for all the developers in a single building. An enterprise license would be for numerous developers in multiple buildings.

Q: Does the encryption libary work with ASP.NET?
A: Yes, the encryption libary works with ASP.NET, Winforms, Web Services, and Windows Services

Q: What is a salt and do I need to use it?
A: A cryptography salt is combined with a password key to vary the password for encryption or hashing. While not required, it can help better protect your information. For more information see Crypographic Salts

Q: What is an initialization vector?
A: An initilization vector is used as a starting point for encryption streams. It is another way of varying the encryption output. For more information see Initialization Vectors

Q: How can I get the best performance when encrypting?
A: Make an static instance of the encryption libary to use throughout your application.

Q: How do I determine if a file or string is encrypted?
A: Use some sort of prefix such as @ENCRYPTED@ and then remove it before decrypting.

Q: I am receiving the error: Could not load file or assembly 'KellermanEncryptionLibrary A: Do a Clean Solution and Rebuild Solution.

Q: Is the encryption library compatible with COM?
A: No.

Q: Do you plan to add COM support?
A: There are no plans at this time to add COM support.

Q: Does the encryption library support PGP?
A: Not currently, but if we get enough requests for it, we may add it.

Q: Does the encryption library work with .NET 1.1?
A: No.

Q: What happens when the trial expires?
A: An exception is thrown, indicating that the trial is expired.

Q: How can I set key length to 256 bits when using Rijndael or Twofish??
A: The bits are set to the highest possible for every algorithm. If a key is too short, it is padded with zeroes. If it is too long, it is truncated.


"The cost of implementing my projects is significantly reduced having implemented the Kellerman Software Encryption Library. The documentation for the API is minimal and simple to develop with."

Robert Lockwood

Date Version Description
8/14/2006 1.0 Initial Release. The .NET Encryption Library is a component that allows symmetric encryption, asymmetric encryption, compression, and binary encoding.
11/17/2006 1.01 This update adds the Adler32 checksum and improves the secure file erase by overwriting files with random bytes.
2/15/2007 1.02 This update adds a demo in VB.NET
3/17/2007 1.03 These hashing algorithms are now supported, Whirlpool, Tiger, MD2, MD4, FCS16, and FCS32.
6/15/2007 1.04 The June 2007 issue of Visual Studio magazine is on news stands. The Kellerman Encryption Library has won a Visual Studio Magazine 2007 Readers Choice Merit Award for the Security and Copy Protection Category.
7/26/2007 1.05 This update includes the ability to run the encryption library under medium trust web servers.
10/27/2007 1.07 This update fixes a file decryption issue with Twofish and Blowfish; other algorithms are unaffected by this problem.
2/20/2008 1.09 New features include CRC32 for strings, Adler32 for strings, and 6 Digit PIN generation.
7/16/2008 1.0 algorithm?
5/30/2009 1.11 By customer request, it is now possible to encrypt/decrypt files without base64 encoding.
8/19/2009 1.14 By customer request, the encryption Padding Method is now available.
7/9/2010 1.15 This release includes a .NET Framework 4.0 build that is compatible with Visual Studio 2010.
6/27/2011 1.17 This fixes a trial mode issue for the .NET 4.0 framework in a medium trust environment.
2/3/2012 1.18 This fixes an issue for the twofish algorithm when the password is longer than the key length. Also, by customer request to get the key length of each symmetric algorithm.
9/29/2012 2.0 By customer request these features have been added: ability to encrypt streams, RSA key generation, RSA byte encryption, RSA string encryption, RSA file encryption.
12/21/2012 2.01 This update fixes an issue for Adler32 calculations not closing the file stream immediately.
7/10/2013 2.02 This update fixes an installation conflict with another Kellerman Software product.
7/12/2013 2.03 The help file has been completely reworked with numerous examples. Other new features include MiniLZO compression, CRC32 for streams, and Adler32 for streams.
10/3/2013 2.04 Kellerman Software announces a minor update to the .NET Encryption Library. By request, the encryption library has the ability to extend the trial.
11/29/2013 2.05 New build for .NET Framework 4.5 and 4.5.1.
10/04/2014 2.10 This update fixes a licensing exception when running under ASP.NET.
10/19/2014 2.11 This update fixes a compatibility issue with projects using ClickOnce deployments.
9/27/2015 2.14 By customer request, a new property has been added: WriteEncryptionPrefix to turn off @KS@ at the front of encrypted strings.
2/24/2016 2.16 Builds for .NET Framework 4.5.2 and 4.6. The library remains 100% managed code but is now compatible with COM.
3/5/2016 2.18 The output of Whirlpool and Tiger hashes were corrected to match https://www.md5calc.com/
6/18/2016 3.0 Get hexadecimal checksums for Adler32 and CRC32. New Nist hashing algorithims hmac-sha2-256, hmac-sha2-256-96, hmac-sha2-384, hmac-sha2-512, hmac-sha2-512-96, hmac-sha1-96, hmac-md5-96. Ability to convert a hexadecimal string into a byte array. The NuGet package now includes the help file.
8/9/2017 4.0 New release contains a version which is compatible with .NET Core V1.1 and higher.
9/14/2019 4.11 Builds for .NET Framework 4.7, 4.7.1, 4.7.2, and 4.8.
6/13/2020 5.00 New .NET Standard 2.0 Library. New Symmetric Algorithms: ChaCha20, Idea, RC4, and XTEA. New Asymmetric Encryption: ECDH (Elliptical Curve Diffie Hellman) shared secret encryption is supported. New Hashing Algorithms: Grindal256, Grindal512, RadioGatun32, RadioGatun64, GHash, Ripemd160, SKEIN, Blake, Keccak, Elf, and SumBSD. New Secure Erase Algoriths: Department of Defense 5220.22-M, Department of Defense DoD 5220.22-M ECE, Gutmann, US Navy NAVSO P-5239-26, Schneier, German VSITR, US Army AR 380-19, Russian GOST R 50739-95 Version 2, and US Air Force AFSSI-5020. Now supports format Preserving Encryption. Now supports One Time Passwords.