This book presents a collection of 36 pieces of scientific work in the areas of complexity theory and foundations of cryptography: 20 research contributions 13 survey articles and 3 programmatic and reflective viewpoint statements. These so far formally unpublished pieces were written by Oded Goldreich some in collaboration with other scientists. The articles included in this book essentially reflect the topical scope of the scientific career of Oded Goldreich now spanning three decades. In particular the topics dealt with include average-case complexity complexity of approximation derandomization expander graphs hashing functions locally testable codes machines that take advice NP-completeness one-way functions probabilistically checkable proofs proofs of knowledge property testing pseudorandomness randomness extractors sampling trapdoor permutations zero-knowledge and non-iterative zero-knowledge. All in all this potpourri of studies in complexity and cryptography constitutes a most valuable contribution to the field of theoretical computer science centered around the personal achievements and views of one of its outstanding representatives.