Parameter definition.

Parameter definition.</p

Architectural design of the calculator based on DNA strand displacement reactions.

(a) The pentahedral pyramid DNA self-assembly structure. (b) The displacement process of a single input strand A'. (c) The displacement process of the adjacent strands (A',B'). (d) The displacement process of the relative strands (A',C').</p

Comparisons of existing studies.

Comparisons of existing studies.</p

The process of encryption by using two models.

The process of encryption by using two models.</p

Comparisons of the probability values.

Comparisons of the probability values.</p

DNA coding combinations.

DNA coding combinations.</p

Four logic gates and truth table.

(a) Input A' and input B' are set as "1" and "0", respectively. The output is "1" only upon the simultaneous addition of strands A' and B'; Otherwise, the output is "0". (b) Both of the input A' and input B' indicate "1"; "0" indicates no input. (c) Add strand C' to displace C firstly, and then define input A' as "1" and input B' as "0". (d) Add strand D' to displace D first, and then define input A' as "1" and input B' as "0".</p

There different displacement processes.

(a) The displacement process when adding A' and B'. (b) The displacement process when adding A' and C'. (c) The displacement process when adding A' and D'.</p

Three different fluorescent color detectors.

Three different fluorescent color detectors.</p

Workflow of DNA cryptography (Encryption process: The plaintext was encrypted with the key after the data processing by using the self-assembly structure; then transmits the fluorescence signal in common channel, and the random numbers were encrypted with steganography and transmitted with the secret information.

Decryption process: the decipher first decrypts the random numbers to restructure the self-assembly structure; the key is generated according to the key parameters, then the key and ciphertext are decrypted by XOR operation using the self-assembly structure; the plaintext information is restored after data processing).</p