Casascius Coins

Casascius Coins, introduced in 2011 by Mike Caldwell, are physical representations of bitcoin designed to make the digital currency tangible. Each coin contains a private key concealed beneath a tamper-evident hologram, allowing holders to access the corresponding bitcoin value. These coins were produced in various denominations, including 1, 10, 25, 100, and 1,000 BTC, and were crafted from materials like brass and gold-plated alloys. The innovative design aimed to simplify bitcoin transactions and storage, especially for those new to the digital currency.