Early 1900s West European Communications Security Device
This cipher device was used by the Ministry of the Interior of Denmark to secure its communications at least from 1910 to 1914, although the device itself may be much older. Individual letters are inscribed on ivory tiles which can be taken out and easily rescrambled around the central disk to change the substitutions for letters. The Danish Ministry probably issued a chart listing the letter arrangements and changes for a stated period, such as daily, weekly, or monthly.
The Italian scholar Leon Battista Alberti wrote an essay in 1466 laying out the principles of polyalphabetic substitution. These principles were used by the U.S. as late as the Vietnam War.
Seen at the National Security Agency’s National Cryptologic Museum, Fort Meade, Maryland.
An observation from someone who is not an expert in cryptography: Cryptography is about converting order (a written or spoken message) to disorder (an encrypted communication with no clear patterns) and vice versa. Thus, I find it interesting that a number of tools for cryptography—especially prior to the digital age—have a physical order or pattern.
Early 1900s West European Communications Security Device
This cipher device was used by the Ministry of the Interior of Denmark to secure its communications at least from 1910 to 1914, although the device itself may be much older. Individual letters are inscribed on ivory tiles which can be taken out and easily rescrambled around the central disk to change the substitutions for letters. The Danish Ministry probably issued a chart listing the letter arrangements and changes for a stated period, such as daily, weekly, or monthly.
The Italian scholar Leon Battista Alberti wrote an essay in 1466 laying out the principles of polyalphabetic substitution. These principles were used by the U.S. as late as the Vietnam War.
Seen at the National Security Agency’s National Cryptologic Museum, Fort Meade, Maryland.
An observation from someone who is not an expert in cryptography: Cryptography is about converting order (a written or spoken message) to disorder (an encrypted communication with no clear patterns) and vice versa. Thus, I find it interesting that a number of tools for cryptography—especially prior to the digital age—have a physical order or pattern.