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International Consulting and Investment Company

Security Printing and DNA Lock™

January 28, 2003
St. Augustine, Florida

Wendell M. Smith, Technology Transfer Group

Security Printing Definition

  • Marks on documents that prove ownership of the document and or the information on the document; and are used to avoid copying and counterfeiting

DNA Lock™ Counterfeit-Resistant Authentication

Carter Bancroft, Ph.D., Mount Sinai School of Medicine, NY

  • Background: “DNA-Based Steganography”
    [Clelland, Risca, Bancroft. Hiding Messages in DNA Microdots. Nature (1999) 399:533-534]

  • Summary: We have extended our DNA-based steganography concept to the development of a secure authentication technique. DNA Lock ™ yields a highly concealed DNA-encoded authentication code that can be detected and read only by authorized personnel, and is thus highly counterfeit-resistant.

Properties of DNA as a Technological Tool

  • DNA is the central repository of information in the cell.

  • DNA stores information efficiently. Four different bases (A, T, G, and C) imply 4^n possible different n-mers.

  • A large number of elements (DNA strands) occupies a small space: 10^12 strands in about 100ul (1/10th of a marble).

  • Hybridization between two DNA strands is strongly sequence- specific. Only complementary strands will hybridize:

Approach by Bancroft Group to Development of DNA-Based Technologies

  • Definition: DNA-Based Technologies are non-biological technologies that employ the biological polymer DNA.

  • Summary: We are developing DNA-based technologies that are based upon:
    – The biochemical properties of DNA, and its enzymes.
    – The techniques of molecular biology that we employ in our biomedical research.

  • Technique Examples: PCR, DNA microarrays (microchips).

DNA-Based Steganography

  • Background: Most current cryptosystems (e.g., RSA) are based upon factorization problems, and are thus vulnerable to attack by powerful (ultimately quantum?) computation.

  • Summary: We have developed “DNA-Based Steganography”- a method for camouflaging a DNA-encoded message within the enormous complexity of the human genome.

    We believe that “breaking” DNA-based steganography would represent an intractable biochemical problem. This technique is thus strongly resistant to either computational or biochemical attacks.

DNA Lock™

Counterfeit-resistant identification of

  • Labels, packaging, or documents.
  • Solid objects (e.g., industrial parts).
  • Liquids (e.g., ink, perfume, forensic samples).

DNA Microarrays: Potential Utility with DNA Lock™

1. Current Use of DNA Microarrays in Biology
DNA Microarray = Ordered Array of Thousands of DNA Samples.

Current Use in Biology: Gene Expression Patterns (“Signatures”).

  • A robot spots up to 10,000 DNA samples (~100×100 matrix) onto a 2cm^2 array on glass or filter.

  • The array is hybridized with colored cellular RNA probe(s) (simultaneous use of two or more probes increases efficiency).

DNA Lock™ Summary and Considerations

    • Authentication DNA Code highly concealed: Ratio of Concealing DNA/Authentication Code DNA = 30 million. This makes detection and counterfeiting of Authentication Code DNA extremely difficult.

    • Concealing DNA can be from any organism(s) in the world.

    • Enormous number of different DNA codes:
      Number of different codes = n4 (where n= # DNA bases in the Authentication Code sequence).

      -10 bases of code yields 410 ~ one million different codes.

      -20 bases of code yields 420 ~ one trillion different codes.


  • Readout: Requires biochemical analysis (PCR, plus DNA sequence analysis), implying no hand-held reader (at present).

  • Proof-of-principle, and publicity: Underlying technology published 1999 in Nature (“Hiding Messages in DNA Microdots”, 399:533).

    – Paper received extensive publicity: multiple newspapers worldwide (including NY Times Science section), websites, plus Bancroft interviews on radio (BBC) and TV (Tokyo).

    – Resulting patent subject of NY Times article, 1/14/02.

  • Patent status: U.S. Patent #6,312,911 “DNA-based steganography”, issued to Bancroft and Clelland, November 6, 2001.

DNA Microarrays: Potential Utility with DNA Lock™

2. Potential Extension of DNA Lock™ to Authentication Tags Containing DNA Microarrays

  • Microarray can be formed on removable filter (or directly on plastic support).

  • All spots contain concealing DNA; only a pattern of spots contains authentication code DNA.
Authentication Procedure:
  1. Remove filter tag from support, attach to authenticated item.

  2. Authentication (Level 1): Determine whether analysis (primer extension) with specific primer yields expected spot pattern. [Spot pattern could represent a binary code (#’s written as 0 or 1).]

  3. Authentication (Level 2): Determine whether DNA product contains the correct authentication code sequence.


We are working in a broad new discipline, “DNA-based technologies”, in which the biological properties of DNA are employed to develop non-biological techniques.

We have recently developed the following technologies:

  • “DNA-Based Steganography”, a technique for hiding messages in genomic DNA, that is resistant to either computational or biochemical attack.

  • DNA Lock™ (derived from DNA-Based Steganography), for counterfeit-resistant authentication of valuable objects.