New coin released by the Royal Australian Mint celebrates the Centenary of the Royal Australian Corps of Signals — but not all is as it seems.

Beneath its golden facade, the $1 commemorative coin features a hidden message in code, just waiting to be cracked. By Tenzing Johnson.

A new coin released by the Royal Australian Mint celebrates the Centenary of the Royal Australian Corps of Signals - but not all is at it seems.

Beneath its golden facade, the $1 commemorative coin features a hidden message in code, just waiting to be cracked.

"[There are] some amazing design features of the coin, capturing our heritage," Royal Australian Corps of Signals Head of Corps, Brigadier Deane Limmer, said.

The commemorative $1 coin, Swift and Sure - Centenary of Royal Australian Corps of Signals.(Supplied: Royal Australian Mint)

Coin rich in symbolism and history

The Royal Australian Corps of Signals was established in 1925, and celebrates 100 years of service in military communications this year.

Part of their role has been to provide communications, information systems and electronic warfare support to the Australian Army and the Australian Defence Force.

"Signallers have been at the forefront of technology, even back in the day," Brigadier Limmer said.

"Morse code only started in 1836, yet signallers were employing it a number of years later. In the First World War, we were working with semaphore [and] in the years since, satellite, cyber, signals intelligence, electronic warfare."

Mint artist Adam Ball's job was to take this history, and put it on a coin.

"[Ball's] brief was to capture a centenary of service and the linkage of Morse code through to binary; the origins of our Corps and to the future; [and] ... our work across the globe, in every conflict, any peacekeeping operation and domestic support operations," Brigadier Limmer said.

The Swift and Sure - Centenary of Royal Australian Corps of Signals memorial $1 coin sitting on an army truck.(ABC News: Tenzing Johnson)

The 'Jimmy' badge is the colloquial term for the Royal Signals Cap Badge, which is a figure of the Roman messenger god Mercury.

As such, Mercury is depicted front and centre on the commemorative coin, standing on a globe, to symbolise the Corps' "global influence and the vital role it has played in international operations".

"A wreath of leaves, inspired by the original Corps badge, honours the service and sacrifice of generations of Signals personnel," added Royal Australian Mint acting Chief Executive Officer Emily Martin.

The coin is titled Swift and Sure, after the Corps' motto in Latin - Certa Cito.

And on the back on the coin, of course, is His Majesty King Charles III's effigy.

Brigadier Deane Limmer holding a blue bar cock pigeon recognising 100 years of the Royal Australian Corps of Signals.(Supplied: CPL Jacob Joseph)

More than a collectible

Ms Martin said it was "such an honour for the Royal Australian Mint to be helping to celebrate the centenary of the Royal Australian Core Signals today".

"It is not just a collectible," she said.

"It is a reminder of the ingenuity, sacrifice and strategic brilliance that has protected Australia for a century [and] a tribute to the men and women who have placed service above self, securing the nation's defences through the power of communications."

Ms Martin added that there would always be a place for collectors at the Mint.

"Whilst we might be seeing a decline in the use of cash in the economy, we still have a lot of collectors and enthusiasts who really value these coins for what they represent and how they tell Australian stories."

The Royal Australian Corps of Signals turns 100 this year, and were honoured with a 100th anniversary parade at the Shrine of Remembrance in Melbourne in February.(Supplied: Department of Defence/ Campbell Myers)

While the new $1 coin is both beautiful and mind-bending, it's not the first time code has been incorporated into a coin.

The Australian Signals Directorate released an encoded 50 cent piece in 2022 to celebrate their 75th anniversary.

It was solved by a 14 year old in a little over an hour.