On 1 September 2022, the Royal Australian Mint released a limited edition fifty cent commemorative coin to celebrate the Australian Signals Directorate's (ASD) 75th anniversary. Fifty thousand coins were produced for purchase by coin collectors and the Australian public, but have since sold out.
We would like to thank the Royal Australian Mint for collaborating with us and helping to celebrate 75 years of ASD.
In tribute to the importance of code breaking and evolution of signals intelligence, ASD experts collaborated with the Royal Australian Mint to design the coin’s unique cryptographic code. There were multiple layers of code on both sides of the coin, with a hidden message revealed after each layer was solved. We’ve provided more information about the history of the codes used on the coin and how to solve them below.