Check 21, also known as the Check Clearing Act for the 21st Century, streamlines the check clearing process by permitting the use of digital images of checks rather than the original documents.

While this reduces operational and administrative costs for organizations, it also poses a security risk if check images are altered at any point during the process. Digital signatures can prevent this by:

  • Exposing modifications to digital images at any point; and
  • Providing certainty about the source of the image.

Digital Signing Par Excellence

The Certicom Security Architecture for Check 21 is a comprehensive solution that allows check application and transport vendors to quickly and cost-effectively add digital signature functionality per ANSI X9.37 security standards. These digital signatures bring strong security to the digital image exchange process. Should a signed image be compromised (e.g. have its value or the name of the payor or payee altered), the signature will not be verifiable, and the check will not be cleared.

The Certicom Security Architecture uses Elliptic Curve Digital Signature Algorithm (ECDSA), one of the strongest and fastest implementations available for digital signatures. Vendors such asUnisysare already using Certicom technology to meet their security requirements.


Using the Certicom Security Architecture with ECDSA for digital signing affords many advantages to solution developers, including:

  • competitive differentiation with added security value to meet customers' growing security requirements
  • check image security that meets current standards and will evolve with changing standards
  • strong security that doesn't bog down application performance
  • small signatures that protect the images throught the seven-year archive requirement
  • high-efficiency ECC enables signing and verification of thousands of images per minute - faster than other recommended algorithms

Key Modules

The Certicom Security Architecture employs a modular set of security protocol services, software cryptographic providers and middleware - all pulled together by a single, intuitive API and developed to meet the Check 21 requirements of:

  • digital signature verification
  • certificate chain validation to trusted Check 21 root
  • CRL parsing and verification

Certicom Professional Services

Offset the costs and challenges of implementing your security solution. Call on Certicom Professional Services for help. We've developed successful security solutions for numerous customers in the financial services industry, including Unisys, Sterling Commerce and Sybase.