DNA Origami Turns Secrets into Molecular Morse Code: Multi-Key Nano-Safe Resists Single-Party Attacks

Mathematics has protected banking operations, government communications, and personal correspondence for decades. Modern cryptography converts plain text into unreadable data without the correct key. However, growing computational power and the rise of quantum computers are driving the search for new methods of storing secrets. Chinese researchers have now proposed using DNA for this task.

Scientists created a multi-level encryption system based on DNA origami. Molecules assemble into tiny rectangular plates where the message is written using dots and dashes in Morse code. After encoding, the flat structure folds into a tube that physically hides the pattern. The data can only be read with the correct molecular key that unfolds the tube.

DNA has long attracted information-storage specialists. The molecule can hold enormous volumes of data, and its base sequence can be programmed with high precision. In biomolecular cryptography, protection relies not on conventional computer algorithms but on the properties of DNA, proteins, bacteria, and their reactions.

The researchers chose DNA origami for the new system. This method folds a long single-stranded molecule into a desired shape using hundreds of short helper strands called staple strands. Each staple binds to a specific region of the main molecule and forces it to bend at the right location.

The device is built from flat DNA rectangles. Researchers placed elements representing dots and dashes on their surfaces. Dots were created from small DNA loops resembling dumbbells. Dashes were formed through a chain hybridization reaction in which short molecules sequentially connect to create a long double-stranded track.

The arrangement of dots and dashes encoded letters according to a pre-defined table. After writing the message, scientists attached special locking strands to the edges of the rectangle. Complementary sections found each other, joined, and pulled the plate into a tube.

Once folded, the pattern was hidden inside the structure. A scanning instrument could no longer detect the positions of dots and dashes, so the contents remained concealed even with physical access to the sample.

All messages were divided into blocks of equal size. This ensured that the length and shape of the DNA construct did not reveal the number of characters or the structure of the original text. An observer saw identical tubes regardless of the data inside.

Decryption required a verification key, denoted Vk, consisting of six types of unlocking DNA strands. Their sequences matched the locking regions exactly and bound more strongly than the tube edges bound to each other.

Adding the key caused the locking connections to break apart and the tubular structure to unfold back into a flat rectangle. Reaction efficiency reached 99.7 percent. Folding took about eight hours, while the reverse process completed in several minutes.

The unfolded surface was examined using atomic force microscopy. The method does not use ordinary light; a thin probe scans the sample and records minute height changes, allowing the instrument to build images of objects only a few nanometers in size.

The resulting image clearly showed the dots and dashes. Researchers compared the pattern with the code table and reconstructed the original message. The full cycle was tested on the phrase “JUNE6 INVASION NORMANDY”.

Transitioning between flat and tubular forms provides 2,576 possible key variants. Without the correct set of unlocking strands, the structure does not unfold and the internal pattern remains inaccessible to scanning.

Protection operates on multiple levels. First, content is converted into a sequence of dots and dashes. The elements are then recorded on a DNA nanostructure. The surface folds to hide the pattern physically. Recovering the message requires both the correct molecular key and equipment capable of resolving the pattern on the unfolded plate.

The entire encryption and decryption process took approximately ten hours. Electronic systems perform similar operations far faster, so DNA origami is not yet suitable for everyday correspondence or real-time data transmission.

The main value of the experiment lies not in speed. The scientists demonstrated that DNA molecules can be programmed to perform several cryptographic operations: recording a message, changing the carrier’s shape, concealing data, and revealing it only after the correct key is added.

The DNA system remains a laboratory prototype requiring sophisticated equipment and lengthy chemical reactions. Nevertheless, the work shows that future information-protection tools may rely not only on mathematical algorithms but also on the physical properties of programmable molecules.