Week 6: Currency and the state's own arms race

Why banknotes look the way they do — a design history driven entirely by an ongoing contest with forgers, and what that contest teaches about design.

31 August 2027

No object on earth has had more design attention paid to defeating its own forgery than a banknote, and every feature that makes a modern note strange to look at — the microprinting, the colour-shifting ink, the raised intaglio you can feel with a fingernail, the deliberately uneven serial-number kerning — is a scar from a specific historical attack. Read a note’s security features in order and you’re reading a hundred-year argument between engravers and forgers, each move answered by the next. It’s the cleanest example the semester has of a general principle: a defence designed against a known attack only holds until the attack changes, and the attacker always moves first.

Outline#

• a short history of note design as an arms race, feature by feature
• the counterfeiter’s asymmetry: the state must defend every note, the forger only needs one to pass
• what banknote security teaches about designing any anti-forgery system, including a digital one
• Assignment 1, “The Convincing Copy,” is due at the end of this week — see the assessment page for the studio-note requirement