JP2004304608A - Encrypted information transmitting method and decryption method using biopolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel method for transmitting and decrypting the encrypted information in which a cryptogram can be transmitted in safety without previously sharing a key by applying biotechnology. <P>SOLUTION: A collection of biopolymers having many kinds of sequences is used as an information transmitting medium. In the method for transmitting encrypted information, a transmitter transmits encrypted information locked with a first key and false information to a receiver, and then transmits the encrypted information sent back from the receiver while being locked with a second key back to the receiver while unlocking the first key. In the decryption method, the receiver transmits the encrypted information received from the transmitter while being locked with the first key back to the transmitter while further locking with the second key, and then decrypts the encrypted information by unlocking the second key of the encrypted information sent back from the transmitter while unlocking the first key. Different biopolymers attached to the biopolymers of transmitting media of the encrypted information and false information can be used as the first key and second key. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technology for constructing a secure cryptographic transmission system using biotechnology, which is rapidly progressing.
[0002]
[Prior art]
Currently, the most widely used communication system is a system that distributes an electric signal (including a case where an electromagnetic wave is used as a carrier) using wireless or wired communication. These systems can deliver data quickly between any regions, but can also be easily intercepted by third parties. Even if the information is encrypted, the detection of the encrypted communication itself and the identification of the sender and receiver thereof can be easily performed by a third party. Moreover, since it is an electric signal, a large amount of data can be input to the computer at a time, and the cryptanalysis can be performed quickly. Since an electronic computer is actually the only machine that analyzes the encryption, the encryption can be easily analyzed, especially if a communication device having a high affinity with the computer is used.
[0003]
At present, the Internet, which is the standard for telecommunications, is extremely easy to be intercepted because communication data is relayed through third-party sites. Therefore, it is desirable to avoid using the Internet when security is required rather than transmission speed for information transmission. In such a digitized society, communication by mail (especially commercial transactions) continues, partly because of the above reasons.
[0004]
On the other hand, it is also conceivable to use DNA as an encryption transmission medium. If communication is performed by writing information into DNA, encrypting it, and carrying it, the security of the information will be dramatically improved. Because itself even small DNA of about 10 ³ bases can store 2kbit stuff information, yet every single DNA is at 1μm or less in length, because it is impossible to recognize with the naked eye. Furthermore, such small-scale DNA has no toxicity, and even large-scale DNA is a universal substance present in all living organisms. As a method of transmitting the code, a liquid containing DNA can be soaked in paper and sent as a general letter, or the DNA can be attached to another substance and transported. It is also possible to embed DNA in living cells. In conclusion, it is meaningful for a third party to detect the existence of the encrypted communication itself, knowing the unique sequence of the DNA used for the communication, conducting a DNA test on all substances circulating between the two, and making sense. It is extremely difficult unless information is reconstructed to eliminate chance.
[0005]
Currently, biotechnology using DNA is developing as a major industry. Although the purpose is medical, automation of DNA synthesis, replication, analysis, etc. is progressing at a rapid speed. In addition, the miniaturization and price reduction of automatic machines are steadily increasing, and private companies can easily purchase even non-specialized research institutions if they follow the guidelines. Therefore, if a cryptographic system using DNA can be realized for communication (such as transmission of personal information) in which security is given priority over communication speed and ease of handling, the impact on society will be extremely large.
[0006]
Against this background, US C.I. An experiment on DNA coding was performed by the group of Bancroft (Non-Patent Document 1). This utilizes a cryptographic technique (a type of steganography) that allows true information to be mixed into a large number of false information. In this encryption method, true information cannot be known unless the base sequence of a specific site of the key DNA is known.
[0007]
However, even in this encryption method, it is necessary for the sender and the receiver to share a key (base sequence of a specific portion) in advance, and the security becomes a serious problem. This is called the key distribution problem and is the most important problem in cryptographic communication.
[0008]
[Non-patent document 1]
C. T. Cllland, V .; Risca, and C.E. Bancroft, Nature Vol. 399, 10 June 1999, pp. 533-534
[0009]
[Problems to be solved by the invention]
An object of the present invention is to provide a new technology that can securely transmit encryption without applying a key in advance by applying biotechnology.
[0010]
[Means for Solving the Problems]
The technology provided by the present invention includes an encrypted information transmission method and an encrypted information decryption method.
[0011]
The encrypted information transmission method of the present invention uses a set of biopolymers having various types of sequences as an information transmission medium, and transmits the encrypted information and the false information with the first key to the receiver by the sender. Then, the encrypted information returned from the receiver using the second key with the second key is returned to the receiver using the first key.
[0012]
The encrypted information decryption method of the present invention uses a collection of biomacromolecules having various types of sequences as an information transmission medium, and uses a first keyed encryption received by a receiver together with false information from a sender. The encrypted information is returned to the sender by further applying the second key, and the sender opens the first key and decrypts the encrypted information by opening the second key of the returned encrypted information. I do.
[0013]
In the present invention, it is preferable to use a nucleotide such as DNA or RNA as a biopolymer for writing the encoded information.
[0014]
According to the present invention, it is possible to hide locked true encrypted information in a very large number of fake information. In order for a third party to steal the key, a lot of effort is required, as it took a long time for a large project to analyze the entire nucleotide sequence of the human genome. Decoding information is extremely difficult. Thus, a truly secure cryptographic communication means is created by the present invention.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to a technique for securely delivering true information using a polymer, particularly a biopolymer such as DNA, without sharing a key in advance. The basic protocol is as follows.
[0016]
In the following, the information sender is Alice, the recipient is Bob, and the eavesdropper (third party) is Eve.
First, the concept of the present invention will be described with reference to FIGS. The sender Alice attaches the key A to the DNA containing the information to be sent (Tom is a lia.), Attaches B and C to the false information, and sends it to the recipient Bob. Bob returns Alice with the key 1 for the intact DNA sent by Alice, and a few keys for Bob's re-keyed by Alice. Next, Alice extracts the DNA with the key A from the returned DNA, removes the key A, and resends it to Bob. Bob extracts the DNA with the key 1 from the retransmitted DNA and reads the information. In this way, Alice can pass Bob the cryptographic information without Alice and Bob teaching each other the key.
[0017]
Next, the operation symbols will be described. x means a base sequence or a DNA having the base sequence. The base sequence is not limited to one type, and there are a plurality of types. Therefore, x also includes the meaning of a DNA set having a certain base sequence. x * y (or simply xy) means a bond between DNAs having base sequences x and y, and x + y means a mixture of DNAs having base sequences x and y. x / y means the remainder after removing the y site when the base sequence x has the base sequence of y, and is 0 when the base sequence x does not have the y sequence.
[0018]
Alice prepares a collection of various types of DNA. The set _{A = {A 0, A 1} , A 2, ..., A i, ..., A M-1} to. A _i represents the type of base sequence of DNA, the number of _{A i} species DNA is sufficiently large and arbitrarily. Alice chooses one arbitrary element from A. The information of this selection is not leaked to the outside and is used as Alice's secret key. Here, _A0 is selected as the secret key. Providing a DNA that _{X 0} is written true of the information you want, the _{A 0} and _{X 0} is bound by DNA helicase. Here, _{X 0} is not limited to one type of DNA. Further, X _i (i ≠ 0) in which the false information is written is prepared and combined with A _i (i ≠ 0). Thereafter, the combined mixture of A _i X _i (i = 0, 1, 2,..., M−1) is sent to Bob. The A _i X _i, can also be added biopolymers capable of cleaving a particular sequence site.
[0019]
Bob also prepares a collection of various types of DNA. The set _{B = {B 0, B 1} , B 2, ..., B k, ..., B N-1} to. Bob chooses one arbitrary element from B. The information of this selection is used as Bob's secret key without leaking to the outside. Here, _B0 is selected as a secret key. Bob divides the mixture sent from Alice into two, and combines B ₀ with one to create A _i X _i B ₀ (i = 0, 1, 2,..., M−1). The remaining mixture, cutting the _{A i} and _{X i,} make a new binding _A i _{X j} by coupling again. Further, B _k (k ≠ 0) is added and combined to form a mixture of A _i X _j B _k (k ≠ 0). The combination of A _i , X _j , B _k is random, and a new mixture of A _i Y _j B _k (k ≠ 0) may be added. The two _A mixture obtained by mixing the _{i X i B 0 (i =} 0,1,2, ..., M-1) + A i X j make _B k a (k ≠ 0), sends it to Alice.
[0020]
Alice _{A i X i B 0 (i} = 0,1,2, ..., M-1) received from Bob separating DNA containing the _{A 0} from _{+ A i X j B k (} k ≠ 0). Further, the mixture X ₀ B ₀ + X _j B _k (k ≠ 0) formed by cutting these DNAs and excluding A ₀ is sent back to Bob.
[0021]
Bob isolating DNA containing the mixture _{X 0 B 0 + X j B} k (k ≠ 0) from _{B 0} received from Alice. Then, finally leaving only the X _0, Bob may receive information from Alice.
[0022]
Now, Eve can withdraw a portion of the DNA mixture in transit. The extracted mixture is A _i X _i (i = 0, 1, 2,..., M−1), A _i X _i B ₀ (i = 0, 1, 2,..., M−1) + A _i X _j B _k (k ≠ 0) and X ₀ B ₀ + X _j B _k (k ≠ 0). Here, the mixture A _i X _i (i = 0, 1, 2,..., M−1) and A _i X _i B ₀ (i = 0, 1, 2,..., M−1) + A _i X _j The entire base sequence of each of B _k (k ≠ 0) is checked, and the data is stored in the computer. _{Then, A i X i B 0 (} i = 0,1,2, ..., M-1) was combined with most types of _A i _{X i} in _{+ A i X j B k (} k ≠ 0) B if searching _k by an electronic computer, can be estimated that _{B k B 0} and. However, even if the length of A _i X _i is about 10 ³ bases and the type is 10 ⁶ , analysis of more than the human genome (about 3 billion bases and the number of chromosomes can be classified in advance) must be performed. . The difficulty of examining the entire nucleotide sequence is also evident from the size and length of the genome project.
[0023]
【Example】
First, the information sender Alice prepares DNA binding A ₀ * LA * X ₀ * LB. It is written the information you want to convey to the X _0. Writing a information itself to be written this time to X ₀ with its decryption key is encrypted, it is safer. For example, the length of _{A 0} is from 10 to about 20 bases, LA 6 to 20 bases, _{X 0} is 100 to 1000 bases, LB 6 bases, _{B 0} is designed as a guide length of about 10 to 20 bases I do. LA and LB have sites that can be cleaved by different restriction enzymes. For example, as shown in FIG. 3, the design is such that LA can be cut with EcoRI and LB can be cut with ApaI. The name of the restriction enzyme that cuts the LB (here, Apa I) is reported to Bob, the information recipient in advance (may be known). If PCR amplification is carried out in a final process, adding a new nucleotide sequence to the right of the LA, it is better to B ₀ and the length of the same degree. X ₀ is better having a sequence that is not cleaved by Eco RI and Apa I.
[0024]
Next, Alice prepares many types of dummy DNA. Natural DNA may be used, but the molecular weight is about the same as A ₀ * LA * X ₀ * LB. What we have the nucleotide sequence of A ₀ in these DNA excluded by affinity separation method. Further, among these DNAs, those having an LA base sequence are extracted this time by affinity separation. The dummy DNA that has been subjected to these processes is referred to as dA. Then, A ₀ * LA * X ₀ * LB and dA are mixed. At this time, the more than sure _{A 0 * LA * X 0 *} LB of dA, Maxam _{- A 0 * LA * X 0} * so that the nucleotide sequence of the LB can not be read by Gilbert method. Alice adds Apa I to this mixture, cuts the LB to a sticky end, and sends it to Bob.
[0025]
Bob are prepared in advance LB * _{B 0.} The length of the B ₀ is set to about 10 to 20 bases. LB * B ₀ is made cohesive with Apa I.
[0026]
Bob divides the mixture (A ₀ * LA * X ₀ * LB + dA) sent from Alice into two. On one of the liquid, the LB * _{B 0} which had been prepared was added, and advances the coupling between cohesive ends with DNA _helicase, make _{A 0 * LA * X 0 *} LB * B 0 + dA * B 0. A ₀ * LA * X ₀ * LB * B ₀ is the longest DNA containing X ₀ in the cryptographic transmission process here, and has a structure schematically shown in FIG.
[0027]
The DNA in the remaining solution is blunt ended by enzymatic enzymatic termination. Furthermore, it is variously digested with a type I restriction enzyme other than Apa I. (Alice may publicize the use of Eco RI, and Bob may cut the DNA in this solution with Eco RI.) The cut DNA is recombined with DNA ligase to produce DNA with the new sequence. Then, it excludes those that have a nucleotide sequence of B ₀ in these DNA by affinity separation method. The dummy DNA after these processes is called dB.
[0028]
Bob returns to Alice a mixture of the two (including A ₀ * LA * X ₀ * LB * B ₀ + dA * B ₀ + dB).
[0029]
Alice, a DNA having a nucleotide sequence of A ₀ from a mixture returned from Bob extracts by affinity separation method. Then, after cutting the DNA in the solution in Eco RI, now excludes _{A 0} cleaved by affinity separation method. Thus obtained solution _(including the _{LA * X 0 * LB * B} 0 + dB / A 0) is returned to Bob.
[0030]
Bob, the DNA from the _{LA * X 0 * LB * B} 0 + dB / A 0 sent back from Alice has the base sequence of the _{B 0} is extracted by affinity separation method. By this operation, only LA * X ₀ * LB * B ₀ can be selected. Bob The DNA Maxam - can be known read by Gilbert method, securing the contents of the X _0.
[0031]
In the above example, LA in LA * X ₀ * LB * B ₀ is a cohesive end because Alice has been digested with Eco RI. If Alice publicizes the use of Eco RI, Bob will be able to repair this portion of the sequence to a complete LA sequence. This action, LA portion becomes 6 bases, it is possible to perform the PCR (polymerase chain reaction) amplification by the primers of LA and B _0, it becomes possible to increase the sensitivity of the reading. Alternatively, pre-LA to known adding a new nucleotide sequence on the right side of the further it is possible to increase the sensitivity of the reading if B ₀ and the length of the same degree.
[0032]
Although the present invention has been described above, the features of the present invention will be described below with various aspects thereof.
(Supplementary Note 1) Using a set of biopolymers having various types of sequences as an information transmission medium, the sender sends the encrypted information and the false information with the first key to the receiver, and then the receiver A method for transmitting encrypted information using a biopolymer, wherein the encrypted information returned with the second key is opened to the receiver with the first key opened.
(Supplementary Note 2) Another biopolymer is added to each of the biopolymers of the encrypted information and the false information transmission medium, and the biopolymer to be added to the biopolymer of the encrypted information transmission medium is added to the biopolymer. An encrypted information transmission method using the biopolymer according to Appendix 1, which is used as one key.
(Supplementary Note 3) In order to open the first key of the encrypted information returned from the receiver, the first key is obtained from a set of biopolymers as a medium for transmitting the encrypted information and the false information returned from the receiver. The biopolymer of the transmission medium containing the biopolymer is separated, the separated biopolymer is cut, and the set of biopolymers obtained by excluding the first key biopolymer is returned to the receiver. 2. A method for transmitting encrypted information using a biopolymer according to claim 2.
(Supplementary note 4) Encryption using the biopolymer according to Supplementary note 2 or 3, wherein another biopolymer capable of cleaving a specific sequence site is added to the biopolymer of the transmission medium of the encrypted information and the false information. Information transmission method.
(Supplementary Note 5) The method for transmitting encrypted information using a biopolymer according to supplementary note 4, wherein a biopolymer that is cleaved by a restriction enzyme is used as the further biopolymer.
(Supplementary Note 6) Separation of the biopolymer of the transmission medium containing the biomolecule of the first key from the set of biopolymers returned from the receiver, and separation of the biopolymer of the first key cut 4. The method for transmitting encrypted information using a biopolymer according to claim 3, wherein the exclusion is performed by an affinity separation method.
(Supplementary Note 7) Using a set of biopolymers having various types of arrangements as an information transmission medium, the receiver adds the second keyed encrypted information received from the sender together with the false information to the second encrypted information. A biopolymer is characterized in that the key is further returned to the sender, and the sender opens the first key and decrypts the encrypted information by opening the second key of the returned encrypted information. The encryption information decryption method used.
(Supplementary Note 8) The set of biopolymers containing the first locked encryption information received from the sender is divided into two, and another polymer is added to one set of biopolymers, This other biopolymer is used as the second key, and the other set of biopolymers is used as a biopolymer that is a medium for transmitting encrypted information and pseudo information and a separate biopolymer that has been added thereto. Biomolecule obtained by forming a new bond between the biomolecule of the transmission medium and the above-mentioned separate biopolymer by being cut into molecules and then bonding, and further bonding another biopolymer to this bond 8. The method for decrypting encrypted information using a biopolymer according to claim 7, wherein the set is returned to the sender together with the set of biopolymers to which the biopolymer of the second key is added.
(Supplementary note 9) The bioheight according to Supplementary note 8, wherein the sender separates the biopolymer of the transmission medium having the biopolymer of the second key from the set of biopolymers returned by opening the first key. A method for decrypting encrypted information using molecules.
(Supplementary note 10) The code using the biopolymer according to Supplementary note 8 or 9, wherein a biopolymer to which a specific sequence site can be cleaved is used as a biopolymer of the encrypted information and pseudo information transmission medium. Information decryption method.
(Supplementary note 11) The biomolecule according to any one of Supplementary notes 8 to 10, wherein a biopolymer to which a specific sequence site can be cleaved is used as a biopolymer for transmitting the encrypted information and the false information. A method for decrypting encrypted information using polymers.
(Supplementary note 12) The biomolecule according to supplementary note 9, wherein the biopolymer of the transmission medium having the second key biopolymer is separated from the set of biopolymers returned from the sender by an affinity separation method. A method for decrypting encrypted information using molecules.
(Supplementary note 13) The method for decrypting encrypted information according to any one of Supplementary notes 7 to 12, which includes amplifying a biopolymer having a specific sequence in a part of the site.
[0033]
【The invention's effect】
The present invention is a technique for transmitting information without sharing a key in advance as a secure cryptographic communication system. With the rapidly evolving biotechnology, it is possible to hide real information in a very large number of false information. As long as the key is not known, the true information cannot be determined in principle. In order for a third party to steal the key, a great deal of effort is required as described above. On the other hand, it is easy for the recipient to retrieve the true information. Therefore, the present invention creates a secure communication means by a method other than the electric / optical communication.
[Brief description of the drawings]
FIG. 1 is a first diagram illustrating the concept of the present invention.
FIG. 2 is a second diagram illustrating the concept of the present invention.
FIG. 3 is a diagram showing the base sequences of LA and LB used in Examples.
FIG. 4 is a diagram schematically showing a base sequence structure of A ₀ * LA * X ₀ * LB * B ₀ used in Examples.

Claims (5)

Using a set of biopolymers having various types of arrays as an information transmission medium, the sender sends encrypted information and fake information with the first key to the receiver, and then the receiver sends the second key A method for transmitting encrypted information using a biopolymer, wherein the returned encrypted information is opened to a receiver with a first key. The first key is obtained by adding another biopolymer to each of the biopolymers of the encrypted information and the false information transmission medium and adding the biopolymer to the biopolymer of the encrypted information transmission medium. And, in order to open the first key of the encrypted information returned from the receiver, the first key of the first key from the collection of biopolymers of the transmission medium of the encrypted information and the false information returned from the receiver Separating the biopolymer of the transmission medium containing the biopolymer, cutting the separated biopolymer and returning the set of biopolymers obtained by eliminating the first key biopolymer to the receiver, A method for transmitting encrypted information using the biopolymer according to claim 1. Using a collection of biological macromolecules with various types of sequences as an information transmission medium, the receiver can further apply the second key to the first locked encrypted information received with the false information from the sender. A cipher using a biopolymer, characterized in that the cipher information is returned to the sender and the sender opens the first key and decrypts the cipher information by opening the second key. Information decryption method. The set of biopolymers containing the first locked encryption information received from the sender is divided into two, and another macromolecule is added to one set of biopolymers, and this another biomolecule is added. A polymer is used as the second key, and the other set of biopolymers is cut into a biopolymer which is a medium for transmitting encrypted information and pseudo information and a separate biopolymer added thereto. To form a new bond between the biopolymer of the transmission medium and the separate biopolymer, and then assembling the biopolymer obtained by further bonding another biopolymer to the bond. The second key biopolymer is returned to the sender together with the set of biopolymers to which the added biopolymer is added, and the second key is returned from the set of biopolymers returned by the sender with the first key opened. 4. The bioheight according to claim 3, wherein the biopolymer of the transmission medium having the key biopolymer is separated. Encrypted information decoding method using a child. 5. The method for decrypting encrypted information using a biopolymer according to claim 4, comprising amplifying a biopolymer having a specific sequence for a part of the site.

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