The banknote includes a blue 3D security ribbon and a bell and inkwell logo that authorities say are particularly difficult to replicate. These combine with traditional security features, such as a portrait watermark and an embedded security thread that glows pink under ultraviolet light.
The 3D security ribbon - which is plaited into the note, not printed on it - features images of 100s that change into bells and move upwards or sideways depending on how you tilt the paper. Tilting also reveals a green bell within a copper-coloured inkwell to the right of the blue ribbon; the 100 number at the bottom right-hand corner of the banknote also changes from copper to green.
The redesigned banknote, which features a portrait of US establishment father and scientist Benjamin Franklin, also includes raised "intaglio" printing that gives the notes a unique feel, and microprinted words that are difficult to read without magnification.Forgeries
Several research and development has gone into the new note for years, in a joint project with the US Secret Service and the Department of the Treasury.
US authorities says that $100 notes is the most forged of all US banknotes, but accurate figures for the total value of fake cash in circulation are challenging to come by.
The US Secret Service reckons that counterfeit bills account for less than 0.01% of the $1.1 trillion (£683bn) of US money in circulation. It says about $80.7m of counterfeit currency changed hands domestically in 2012, and about $14.5m abroad. The authorities seized $9.7m in counterfeit cash before it could make it in to the US money supply, and seized $56.8m abroad in 2012.