Additional dependencies.

README.md

@@ -9,13 +9,14 @@ Gav Wood, 2014.
 secp256k1 implementation: https://github.com/sipa/secp256k1.git
 Expects secp256k1 directory to be in same path as cpp-ethereum.
 
-(NOTE: secp256k1 requires a development installation of the GMP library.)
+(NOTE: secp256k1 requires a development installation of the GMP library and
+apparently libcrypto.)
 
 A decent C++11 compiler (I use GNU GCC 4.8.1) and a recent version of Boost (I use version 1.53).
 
 CMake, version 2.8 or greater.
 
-sudo apt-get install libgmp3-dev libboost-all-dev cmake
+sudo apt-get install libgmp3-dev libcrypto++-dev libboost-all-dev cmake
 
 ## Building