Cryptographic Development Kits (CDKs)

  • Overview
  • Uses
  • Details
  • Standards
  • Availability


ISC CDKs are flexible, cost effective libraries of linkable cryptographic modules that allow you to add encryption, digital signatures, and message authentication to any application. They reduce the cost of developing secure applications by applying readily available, commercially supported, conventional and public key technology.

ISC CDKs make standards-based cryptographic building blocks available to developers and integrators. Use them to construct secure corporate applications for internal use or OEM products for resale.

Purchase a complete FIPS 140-2 validated library or have us customize one that targets your specific application. ISC can provide implementations of the following federal and industry standards††:

  • NIST Advanced Encryption Standard (AES†)
  • NIST Data Encryption Standard (DES), triple DES (TDES), and DESX
  • NIST Digital Signature Algorithm (DSA) and Elliptic Curve DSA (ECDSA†)
  • Rivest-Shamir-Adleman (RSA) public key technology
  • NIST Secure Hash Algorithm (SHA-1, SHA-224/256/384/512†)
  • MD2/MD5 hash algorithms
  • Diffie-Hellman (DH) and Elliptic Curve Diffie-Hellman (ECDH†) Key Agreement
  • ElGamal, and elliptic curve ElGamal, public key cryptosystems
  • AT&T proprietary exportable DES replacement (EA2)

NSA Suite B algorithms

††A more complete list of the available cryptographic algorithms, protocols, and schemes in the CDK appears on the Standards tab


ISC CDKs can be used to add encryption and authentication to a wide variety of applications:

  • security-enhanced device drivers (such as a encrypting file system filter)
  • e-mail applications
  • electronic funds transfer and EDI
  • document transmission, and
  • messaging and VoIP products

The latest version even provides support for building simple SSL/TLS clients (with one- or two-sided authentication).

Ease of Use

The ISC CDKs provide C/C++ APIs that allow your programmers to rapidly link them into existing code or into new applications under development. Testimonial from a satisfied customer:

I'm very pleased to say that we could integrate your library into our existing system without any problem in development environment. How do I describe it was so easy?

Each kit includes a test file with commented sample source code illustrating the use of each function. This test program also can be compiled to verify the proper operation of the cryptographic engines on your operating system. Virtually unlimited key sizes can be supported for the public key algorithms.

Supported Algorithms and Data Formats

The cryptographic primitives that can be included in a custom CDK for your company's use comply with NSA Suite B recommendations as well as the following Federal and industry standards:


in CDK 8.0
Relevant Standards and Other References
NIST Certificate
AES Supported modes of operation: ECB, CBC, CBC_CS3, CFB-1, CFB-8, CFB-64, CFB-128, OFB, CTR, GCM

FIPS 197; NIST SP-800-38A; NIST SP-800-38B; NIST SP-800-38C; NIST SP-800-38D; CNSS Policy No. 15; RFC 3394; RFC 3565; RFC 5084;
RFC 4869 (NSA) Suite B
RSA FIPS 186-4; ANSI X9.31-1998;
RFC 2437 (PKCS#1v2.0), RFC 3447 (PKCS#1v2.1)
DSA FIPS 186-4; ANSI X9.30-1997
ECDSA FIPS 186-4; ANSI X9.62-1998; IEEE 1363-2000;
NSA Suite B
DH RFC 2631; ANSI X9.42-1998;
IEEE 1363-2000
ECDH NIST SP 800-56A; ANSI X9.63; IEEE 1363-2000; NSA Suite B



Supported modes of operation: ECB, CBC, CFB-1, CFB-8, CFB-32, CFB-64, OFB, CTR

FIPS 46-3; ANSI X3.92 



128- or 192-bit key; supported modes of operation: ECB, CBC, CFB-1, CFB-8, CFB-32, CFB-64, OFB, CTR

FIPS 46-3; ANSI X9.52-1998; NIST SP-800-38A; NIST SP 800-20; NIST SP 800-67



(analysis by J. Kilian and P. Rogaway)



FIPS 185; NIST/NSA specification
RC2 RFC 3217; RFC 2268



RFC 2246 (SSL/TLS);
"Arcfour" internet-draft



FIPS 180-4; ANSI X9.30 Part 2;
ISO/IEC 10118-3:1998
SHA-224/256/384/512 FIPS 180-4; NIST specifications;
NSA Suite B
FIPS 180-4
HMAC-SHA FIPS 198; RFC 2104; ANSI X9.71
HMAC-MD5 RFC 2104; ANSI X9.71
MD2 RFC 1319
MD5 RFC 1321
PRNG FIPS 186-3; FIPS 140-2 Annex C; NIST SP 800-22; NIST SP800-90  
Password Generation FIPS 181
Available Separately
Relevant Standards and Other References
MQV, ECMQV† IEEE 1363-2000, NIST SP800-56A, NIST SP800-78
KEA NIST/NSA specification; RFC 2528; RFC 3279; SDN.701
OAEP RFC 2437 ( PKCS #1v2.0); RFC 3560; IEEE 1363-2000 
CAST-128 RFC 2144 
RIPEMD-160 ISO/IEC 10118-3:1998; A. Bosselaers' website; RFC 2857

CDK 8.0, which has recently received an updated FIPS 140-2 compliance certification by NIST, is the cryptographic engine used in the most recent builds of all ISC products.

Additional cryptographic algorithms (that were included in CDK 7.0) have been moved to a auxiliary protocol library to simplify the FIPS 140-2 verification process. In CDK 7.0, these mechanisms, protocols and schemes included:

  • X.509v3 certificate and CRL handling (RFC2459, RFC3279, RFC3280, NIST SP 800-15)
  • PKCS#7/#8/#10/#12 PDU creation and parsing
  • basic S/MIME v3 CMS functions for PDU creation and parsing (RFC3370. RFC3851, RFC3852)
  • key derivation functions for PKCS#5 PBE and various ANSI and PKCS#1/#3/#5/#8 (RFC2313-2315) padding, encoding, and decoding functions
  • RFC3394 key wrapping and unwrapping
  • pseudo-random number generation, primality testing, and routines for low-level modular exponentiation and other high-precision arithmetic operations (in rings of integers, finite fields, and elliptic curves)
  • simple SSL/TLS client support


    ANSI/ABA Security Standards for Financial Services
    The IEEE 1363 website

Although no longer part of Suite B, ECMQV is available from ISC for national security purposes under an NSA sublicense.

Standards Compliance


CDK 8.0 was awarded NIST FIPS 140-2 Level 1 Certificate No. 3105. It was also NSA Suite B compliant (while that recommendation was in effect) and meets or exceeds all DoD/CNSS NSTISSP #11 acquisition requirements. Its FIPS 140-2 Certification was performed by a NIST-accredited laboratory that did source code level validation of all supported FIPS approved algorithms and security interfaces. Review and oversight was provided jointly by NIST and CSE. While not a "Type 1 product," it has been approved by NSA "for use on classified systems."

FIPS 140-2 logo


Only products containing FIPS 140-2 validated security modules may be purchased and used for the processing of sensitive data by agencies of the U.S. Federal Government. Such products are also recommended by the Government of Canada.

Commercial Availability

ISC CDKs are available for the following platforms:

  • Windows and Windows Server (all active 32- and 64-bit versions)
  • RHEL 7 and all similar Linux distributions (x86, i64, IA64, MIPS, etc.)

CDKs can also be supplied (upon demand) for most other desktop, mobile, and embedded environments. As proof of its portability, ISC has shipped CDK builds for the following target platforms:

  • Mac OS X
  • Android, iOS, Windows Phone/ARM (including kernel mode)
  • Solaris 8,9,10/SPARC, Solaris 8,9,10/x86_64 (32- and 64-bit)
  • HP-UX 10.x/11.x/11.i, OpenVMS/AXP
  • IBM AIX (32- and 64-bit)
  • SGI IRIX 6.x
  • Cray UNICOS

using the following compilers (partial list):

  • Microsoft Visual Studio for all Windows platforms
  • GCC (GNU C++) for most Linux and other UNIX-based systems
  • Sun C++ for Solaris/SPARC and /x86-based platforms
  • Green Hill Software's MULTI IDE for embedded PPC-based platforms

CDK libraries can be used in your internal corporation applications or in applications developed for resale; they can even be used to build a security-enhanced device driver that operates in Windows kernel mode. An initial CDK license includes two developer seats; additional developer seats may be purchased as needed. Per copy licensing fees are required for redistribution of the CDK with applications that employ its cryptographic code.

Contact us for fee schedules, header files, and sample code, or for further information on custom libraries.

FIPS 140-2 logo

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