Adding license and initial readme for the modexp core. Provides at least a high level intro to the core and current status.

1 files changed, 49 insertions, 0 deletions

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e6f44a9
--- /dev/null
+++ b/README.md
@@ -0,0 +1,49 @@
+modexp
+======
+
+Modular exponentiation core for implementing public key algorithms such
+as RSA, DH, ElGamal etc.
+
+The core calculates the following functions:
+
+  C = M ** e mod N
+  M = C ** d mod N
+
+  d is the private key exponent.
+  M is a message with a length of n bits
+  e is the exponent with a length of at most 32 bits
+  N is the modulus  with a length of n bits
+  n is can be 32 and up to and including 8192 bits in steps
+  of 32 bits.
+
+The core has a 32-bit memory like interface.
+
+The core is written in Verilog 2001 and suitable for implementation in
+FPGA and ASIC devices. No vendor specific macros are used in the code.
+
+
+## Implementation details ##
+
+The core is using Montgomery multiplication with 32-bit operands. The
+core is iterative and will not be the fastest core on the
+planet.
+
+The core will perform blinding to protect against side channel
+attacks.
+
+
+## FPGA-results ##
+
+No results yet.
+
+
+## Status ##
+
+***(2015-03-13)***
+
+A working, bit exact C model with test cases has been developed and is
+used to drive the HW development. There is also a Java functional model
+available as support for high level undertanding.
+
+Development of the Montgomery product module started. Top level modexp
+module with memories for all operands are being worked on.