# US 11,115,190 B2 · Method of hashing vector data based on multi-scale curvature for vector content authentication > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,190 B2 - Document ID: US11115190B2 - Status: Granted - Kind: B2 - Application number: 15/905,276 - Filed: 2018-02-26 - Published: 2019-07-04 - Granted: 2021-09-07 - Earliest claimed: 2017-02-15 - Assignees: Tongmyong University Industry-Academy Cooperation Foundation - Applicants: Tongmyong University Industry-Academy Cooperation Foundation - Inventors: Sukhwan Lee; Eung Joo Lee - Web page: https://patentgrep.com/patent/US11115190B2 ## CPC - G09C 5/00: Ciphering apparatus or methods not provided for in the preceding groups, e.g. involving the concealment or deformation of graphic data such as designs, written or printed messages - H04L 9/0643: {Hash functions, e.g. MD5, SHA, HMAC or f9 MAC} - G06F 17/16: Matrix or vector computation {, e.g. matrix-matrix or matrix-vector multiplication, matrix factorization (matrix transposition G06F7/78)} - G06T 9/00: Image coding (bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00) - H04L 9/06: the encryption apparatus using shift registers or memories for block-wise {or stream} coding, e.g. DES systems {or RC4; Hash functions; Pseudorandom sequence generators} - H04L 9/3242: {involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC} - H04N 21/83: Generation or processing of protective or descriptive data associated with content; Content structuring - H04L 2209/605: Copy protection - Y02D 30/50: in wire-line communication networks, e.g. low power modes or reduced link rate - G09C: CIPHERING OR DECIPHERING APPARATUS FOR CRYPTOGRAPHIC OR OTHER PURPOSES INVOLVING THE NEED FOR SECRECY - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract The present invention relates to a method of hashing a perceptual vector model based on a multi-scale curvature. According to a first aspect, there is provided a method of hashing a perceptual vector model based on a multi-scale curvature including: generating a multi-dimensional feature coefficient matrix, and obtaining a multi-dimensional intermediate hash coefficient matrix; and obtaining a final binary hash matrix, and enabling the multi-dimensional binary hash matrix to be hierarchically authenticated. In addition, according to a second aspect, there is provided a method of hashing a perceptual vector model based on a multi-scale curvature including: generating a hash by using a hash function; and authenticating a vector model. In addition, an error detection probability for an object attack can be lower by about 2×10−5˜2.8×10−2, and a uniqueness probability is raised by about 0.014. In addition, an entropy can be raised by about 0.875˜2.149. ## Claims ### Claim 1 A method of protecting a digital model comprising a vector model from being tampered or copied, the method comprising: performing rectangular tiling by dividing the vector model into a plurality of rectangular tiles; and generating a hash for a tile among the plurality of rectangular tiles by using a hash function hash(M.R)=(H.θ) based on a multi-scale curvature, wherein M represents the vector model, R represents a random key, H represents a binary hash, and θ represents a parameter, wherein the hash is generated by: re-sampling objects within the tile; calculating a multi curvature for each scale; and generating the binary hash H by using a Lloyd-Max quantizer and a multi-scale curvature hash coefficient based on the key. ### Claim 2 (depends on 1) A method of authenticating a digital model comprising a vector model by using the hash generated according to claim 1, the method comprising: extracting a hash H′ by using a hash extraction function Dehash(M′.R.θ)=H′, wherein M′ represents the vector model to be authenticated, R represents the random key, and θ represents the parameter; and authenticating the digital model by comparing the H′ with the H. ### Claim 3 (depends on 1) The method of claim 1, wherein the performing rectangular tiling includes: generating M={Mj} obtained by dividing the vector model M having a NH×NV size into a rectangular tile having a Nh×Nv size; and generating Mj={pi}i=1|Mj| by extracting polygon and polyline objects among objects belonging to a number of layers within the divided tile, wherein when an entire size of the vector model M is NH×NV, and a ratio scale is 1/RS, the NH×NV size and an actual size of NH×NV is calculated as (NH×RS×10−5)×(NV×RS×10−5)=NH×NV×RS2×10−10[km2]NH×NV×RS2×10−10[km2]. ### Claim 4 (depends on 1) The method of claim 1, wherein, during the re-sampling objects, the objects are re-sampled in a same sampling interval, and re-sampled virtual vertices are generated, when an original object p={vi}i=1p is provided, a sample vertex for the same sampling interval δ is {circumflex over (p)}={vk}, when a sample vertex vk is between and vi−1, the sample vertex vk becomes vk=vk−1+Δdk, ∥Δdk∥=δ, vk=(xk,yk)=(xk−1+Δdx,yk−1+Δdy); f(xk)=yk by a cubic curve polynomial (cubic polynomial curve) expression corresponding to left/right four vertices {vk−2·vk−1·vi·vi−1} which are two previous resampled vertices {vk−2·vk−1} and two ensuing original vertices {vi·vi−1}, herein, the sample vertex vk corresponding to two previous re-sampled vertices{vk−2·vk−1} and two ensuing original vertices {vi·vi+1} is represented as vk−2