Source text: The journey to physicalize Bitcoin has seen significant developments, starting with the iconic Casascius coins in 2011. These coins, created by Mike Caldwell, featured a printed private key affixed to a metal coin, offering a tangible form of Bitcoin. However, regulatory challenges led to their discontinuation in 2013. Subsequent innovations like RavenBit and Opendime sought to address trust and security issues in physical Bitcoin minting. Opendime, developed by Coinkite, introduced a USB device that securely stores Bitcoin keys, requiring physical destruction to access funds. This innovation paved the way for more advanced solutions like Satodime and Tapsigner, which offer enhanced security and usability. Tapsigner, Coinkite's latest product, combines NFC technology with a secure element chip in a debit card form factor, supporting Bitcoin transactions with enhanced security. Priced at around $20, Tapsigner aims to integrate Bitcoin payments into mainstream retail and financial ecosystems, marking a significant step in the evolution of physical Bitcoin. Target language code: tr Translation instructions: This is the news article content. Please maintain the original meaning.