# US 10,769,252 B2 · Method and apparatus for watermarking of digital content, method for extracting information > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,769,252 B2 - Document ID: US10769252B2 - Status: Granted - Kind: B2 - Application number: 15/925,774 - Filed: 2018-03-20 - Published: 2019-09-26 - Granted: 2020-09-08 - Earliest claimed: 2018-03-20 - Assignees: Markany Inc. - Applicants: Markany Inc. - Inventors: So Won Kim; Ji Seop Moon; Min Soo Park; Hyungyu Kim; Euee Seon Jang - Web page: https://patentgrep.com/patent/US10769252B2 ## CPC - G06F 21/16: Program or content traceability, e.g. by watermarking - H04L 9/0825: {using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates} - H04L 9/0866: {involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics} - H04L 9/3239: {involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD} - H04L 9/50: {using hash chains, e.g. blockchains or hash trees} - H04N 21/26613: {for generating or managing keys in general (key distribution for secret or secure communication involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] H04L9/083; network support of key management H04L63/06; key management for network security in communication control or processing H04W12/04)} - H04L 9/3263: {involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements (network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823)} - H04L 2209/608: Watermarking - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method and apparatus for watermarking digital content and a data extraction method are disclosed. The digital content watermarking method includes: generating private and public keys corresponding to the user terminal; generating watermark data containing user identity information corresponding to the user terminal and user details associated with the watermark data; generating encrypted data by encrypting the watermark data and the user details with the private key; transmitting the watermark data, the encrypted data, and the public key to a server; receiving digital content when authorized by the server; and watermarking the digital content with the watermark data. ## Claims ### Claim 1 A watermarking method performed by a user terminal, the method comprising: generating private and public keys corresponding to the user terminal; generating watermark data containing user identity information corresponding to the user terminal and user details associated with the watermark data; generating encrypted data by encrypting the watermark data and the user details with the private key; transmitting the watermark data, the encrypted data, and the public key to a server; receiving digital content when authorized by the server; and watermarking the digital content with the watermark data, wherein the server stores the transmitted watermark data, encrypted data, and public key in the same way in a plurality of databases, respectively, and wherein a different retention period is set for each database, and the data stored in each database is discarded when the retention period expires. ### Claim 2 (depends on 1) The watermarking method of claim 1, wherein the user identity information comprises a user ID corresponding to the user terminal, and the user details comprise at least one among the user's payment details and credit card information for the digital content and the hardware information of the user terminal. ### Claim 3 (depends on 1) The watermarking method of claim 1, further comprising discarding the private key after generating encrypted data. ### Claim 4 (depends on 1) The watermarking method of claim 1, wherein the transmission of the watermark data, encrypted data, and public key from the user terminal to the server is authorized by a third-party or a third-party certificate. ### Claim 5 A watermarking apparatus comprising: a key generator that generates private and public keys corresponding to the user terminal; a data generator that generates watermark data containing user identity information corresponding to the user terminal and user details associated with the watermark data; an encryption part that generates encrypted data by encrypting the watermark data and the user details with the private key; a data transmitter that transmits the watermark data, the encrypted data, and the public key to a server; and a watermark embedder that receives digital content when authorized by the server and watermarks the digital content with the watermark data, wherein the server stores the transmitted watermark data, encrypted data, and public key in the same way in a plurality of databases, respectively, and wherein a different retention period may be set for each database, and the data stored in each database is discarded when the retention period expires. ### Claim 6 (depends on 5) The watermarking apparatus of claim 5, wherein the user identity information comprises a user ID corresponding to the user terminal, and the user details comprise at least one among the user's payment details and credit card information for the digital content and the hardware information of the user terminal. ### Claim 7 (depends on 5) The watermarking apparatus of claim 5, wherein the encryption part discards the private key after generating encrypted data. ### Claim 8 (depends on 5) The watermarking apparatus of claim 5, wherein the transmission of the watermark data, encrypted data, and public key from the user terminal to the server is authorized by a third-party or a third-party certificate. ### Claim 9 A watermarking method performed by a user terminal, the method comprising: generating private and public keys corresponding to the user terminal; generating watermark data containing user identity information corresponding to the user terminal and user details associated with the watermark data; generating encrypted data by encrypting the watermark data and the user details with the private key; transmitting the watermark data, the encrypted data, and the public key to a server; receiving digital content when authorized by the server; and watermarking the digital content with the watermark data, wherein the server stores the transmitted watermark data, encrypted data, and public key in the same way in a plurality of closed blockchains, respectively, and wherein a different retention period is set for each database, and the data stored in each blockchain is discarded when the retention period expires. ### Claim 10 A watermarking apparatus comprising: a key generator that generates private and public keys corresponding to the user terminal; a data generator that generates watermark data containing user identity information corresponding to the user terminal and user details associated with the watermark data; an encryption part that generates encrypted data by encrypting the watermark data and the user details with the private key; a data transmitter that transmits the watermark data, the encrypted data, and the public key to a server; and a watermark embedder that receives digital content when authorized by the server and watermarks the digital content with the watermark data, wherein the server stores the transmitted watermark data, encrypted data, and public key in the same way in a plurality of closed blockchains, respectively, wherein a different retention period may be set for each database, and the data stored in each blockchain is discarded when the retention period expires.