Cynic's Blog

 This is basically a basic building block for constructing a hash function based on Ralph Merkel's PhD thesis which basically states that,  if an appropriate padding scheme is used and the compression function is collision-resistant, then the hash function will also be collision-resistant Block Diagram for Merkel Damgard Construction Important things to consider, Padding IV Padding is basically a long string of 1 followed by as many number of 0s as required and ends with a binary representation of the message length. So to pad a message, 1001101, we pad it with 1001101[100000...00111], where the part inside square brackets are the padded bits.

For those who are familiar with Secugen Devices, might know that there are two function calls to initialize the device API.   The Init(long devName) and  The InitEx(long width, long height, long dpi) As per the official Javadoc, the first one is meant to " Initialize the SecuGen libraries using attached SecuGen fingerprint sensor. This method should be called after Open() is called."  while the second one is for " Initializes the SecuGen libraries using image parameters. Only 8bits per pixel raw images are supported."  For the same function, the C++ documentation says , "Use when running fingerprint algorithm module without a SecuGen reader." I had a use case wherein, I want to do the fingerprint verification/matching at server-side. This made me wonder if I can use the second initialization function at the server end without the device and use the fingerprint matching APIs. I tried using the aforementioned approach, but the InitEx() method was failing ...