Nowadays there are more than 1 thousand and an half cryptocurrencies and (public) blockchains with an overall capitalization of more than 300 Billions of USD. The most famous cryptocurrency (and blockchain) is Bitcoin, described in a white-paper written under the pseudonym of "Satoshi Nakamoto". His invention is an open-source, peer-to-peer digital currency (being electronic, with no physical manifestation). Money transactions do not require a third-party intermediary, such as credit cards issuers. The Bitcoin network is completely decentralised, with all parts of transactions performed by the users of the system. A complete transaction record of every Bitcoin and every Bitcoin userâ€™s encrypted identity is maintained on a public ledger. The seminar will introduce bitcoin and blockchain with a deep view of transactions and some insight on specific applications (e-voting).