# US 2018/0324211 A1 · System and method for prevening denial of service attacks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0324211 A1 - Document ID: US20180324211A1 - Status: Published application - Kind: A1 - Application number: 15/587,990 - Filed: 2017-05-05 - Published: 2018-11-08 - Earliest claimed: 2017-05-05 - Assignees: Manish Doshi - Inventors: Manish Doshi - Web page: https://patentgrep.com/patent/US20180324211A1 ## CPC - H04L 63/1458: {Denial of Service} - H04L 1/00: Arrangements for detecting or preventing errors in the information received {(correcting synchronisation H04L7/00)} - H04L 5/0055: {Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861)} - H04L 67/02: based on web technology, e.g. hypertext transfer protocol [HTTP] - H04L 67/025: for remote control or remote monitoring of applications - H04L 69/16: Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A system for preventing a distributed denial of service (DDoS) attack is disclosed. The system includes a content delivery network (CDN) server connected to Internet, a server connected to the Internet, and a token generator connected to the Internet. The CDN server, the server and the token generator are configured to perform an operation. The operation includes rendering a static login page on a remote computer, receiving entered login information at a token generator through User Datagram Protocol (UDP) from the remote computer, authenticating the received login information by the token generator using an authentication module that is aware of authentication requirements of the server, sending a token and a cookie back to the remote computer, receiving, at the server, a SYN packet with the token from the remote computer, verifying the received token by the web server, and sending an ACK packet back to the remote server from the web server. ## Claims ### Claim 1 A method for preventing a distributed denial of service (DDoS) attack against a server, the method comprising: rendering a static login page on a remote computer; receiving entered login information at a token generator through User Datagram Protocol (UDP) from the remote computer; authenticating the received login information by the token generator using an authentication module that is aware of authentication requirements of the server; sending a token and a cookie back to the remote computer; receiving, at the server, a SYN packet with the token from the remote computer; verifying the received token by the web server; and sending an ACK packet back to the remote server from the web server. ### Claim 2 (depends on 1) The method of claim 1, wherein the token is updated by the server periodically at configurable periods and sent to the token generator and the sending the token includes sending the same token in response to all authenticated requests until a new token is received from the server. ### Claim 3 (depends on 2) The method of claim 2, wherein the server retains at least one immediate previous token for a period of time and the verifying the received token includes verification with the latest token the server has or verification with the immediate past token, wherein the verification includes comparing the received token with a token retained at the server. ### Claim 4 (depends on 1) The method of claim 1, wherein the static login page is rendered from a second server that is separate from the web server. ### Claim 5 (depends on 1) The method of claim 1, wherein the login page does not include an address of a server associated with the login information to be entered in the login page and the token generator is configured to send the address back to the remote computer along with the token. ### Claim 6 (depends on 1) The method of claim 1, wherein the server includes a kernel module to intercept the SYN packet and the token and verify if the token is valid. ### Claim 7 (depends on 4) The method of claim 4, wherein the second server is a content delivery network (CDN) server. ### Claim 8 (depends on 1) The method of claim 1, wherein the cookie includes authentication information according to a requirement set by the server, to enable the remote computer to access services provided by the server. ### Claim 9 (depends on 1) The method of claim 1, wherein the receiving at the server includes receiving a hash of the token along with the SYN packet. ### Claim 10 (depends on 1) The method of claim 1, wherein the server is configured to create a session to serve an incoming request only after the kernel module verifies the token. ### Claim 11 A non-transitory computer readable media comprising programming instructions for preventing a distributed denial of service (DDoS) attack against a server, which when executed by a processor performs an operation, the operation includes: rendering a static login page on a remote computer; receiving entered login information at a token generator through User Datagram Protocol (UDP) from the remote computer; authenticating the received login information by the token generator using an authentication module that is aware of authentication requirements of the server; sending a token and a cookie back to the remote computer; receiving, at the server, a SYN packet with the token from the remote computer; verifying the received token by the web server; and sending an ACK packet back to the remote server from the web server. ### Claim 12 (depends on 11) The method of claim 11, wherein the token is updated by the server periodically at configurable periods and sent to the token generator and the sending the token includes sending the same token in response to all authenticated requests until a new token is received from the server. ### Claim 13 (depends on 12) The method of claim 12, wherein the server retains at least one immediate previous token for a period and the verifying the received token includes verification with the latest token the server has or verification with the immediate past token, wherein the verification includes comparing the received token with a token retained at the server. ### Claim 14 (depends on 11) The method of claim 11, wherein the login page does not include an address of a server associated with the login information to be entered in the login page and the token generator is configured to send the address back to the remote computer along with the token. ### Claim 15 (depends on 11) The method of claim 11, wherein the server includes a kernel module to intercept the SYN packet and the token and verify if the token is valid. ### Claim 16 (depends on 1) The method of claim 1, wherein the server is configured to create a session to serve an incoming request only after the kernel module verifies the token. ### Claim 17 A system for preventing a distributed denial of service (DDoS) attack, the system comprising: a content delivery network (CDN) server connected to Internet; a server connected to the Internet; and a token generator connected to the Internet; wherein the CDN server, the server and the token generator are configured to perform an operation, the operation includes: rendering a static login page on a remote computer; receiving entered login information at a token generator through User Datagram Protocol (UDP) from the remote computer; authenticating the received login information by the token generator using an authentication module that is aware of authentication requirements of the server; sending a token and a cookie back to the remote computer; receiving, at the server, a SYN packet with the token from the remote computer; verifying the received token by the web server; and sending an ACK packet back to the remote server from the web server. ### Claim 18 (depends on 17) The method of claim 17, wherein the token is updated by the server periodically at configurable periods and sent to the token generator and the sending the token includes sending the same token in response to all authenticated requests until a new token is received from the server. ### Claim 19 (depends on 18) The method of claim 18, wherein the server retains at least one immediate previous token for a period and the verifying the received token includes verification with the latest token the server has or verification with the immediate past token, wherein the verification includes comparing the received token with a token retained at the server. ### Claim 20 (depends on 17) The method of claim 17, wherein the server is configured to create a session to serve an incoming request only after the kernel module verifies the token.