In recent years, the field of lightweight cryptography has emerged to offer
security for constrained environments. A plenitude of cryptographic
solutions, from block ciphers, to stream ciphers, and even public key
cryptosystems, were suggested. However, due to some of the constraints
imposed on lightweight implementations, designers need to take a very
unusual point on the security-performance tradeoff curve. In this talk we
will go over several examples, and see what might go wrong when the
optimization is taken one step too much.