Pseudo-Isochromatic challenge for determining whether a user is human or a computer

The end user may send a request to a service provider for access to services and a Pseudo-Isochromatic challenge is generated for the user and the response can be provided as part of the access to service request. The challenge may be a greyscale of image in various colours and hues, the system may generate a second tier of challenges so that people who are colour blind can still correctly respond to a question. Human interactive proofs (HIPS) or captchas are currently used to deter automated registration for web services by automated computer scripts even those using optical character readers (OCR), the use of greyscale or colours makes such automatic reading by spamming applications on the web more difficult. The challenge may be carried out in a trusted computing environment at the device or a third party to create an encrypted digital signature. A cryptographic hash value may be used to morph alphanumeric letters, characters and shapes in to a visual image.