Effective date: September 2, 2026
The operator of oj.uz (the “Operator”) publishes this Privacy Policy to explain how personal data is processed and protected under the Personal Information Protection Act of the Republic of Korea.
The Korean version of this Policy governs. This English version is provided for convenience.
1. Personal data, purposes, legal bases, and retention
| Activity | Data | Purpose and legal basis | Retention |
|---|---|---|---|
| Account management | Email address, username, Auth0 user identifier, email verification status, account creation date, language and programming-language preferences | Registration, authentication, account management, and member services Article 15(1)(4), performance of a contract | Until an account deletion request is completed |
| Submissions and judging | Submitted source code and files, problem, programming language, submission time, judging status, score, results, execution time, and memory usage | Judging programs and providing submission history, statistics, and rankings Article 15(1)(4), performance of a contract | Until a submission deletion request is completed |
| Security and abuse prevention | Submission request IP address, User-Agent, country, region, and city | Security investigations and abuse prevention Article 15(1)(6), legitimate interests | Until deletion of the related submission |
Login sessions, language settings, security cookies, and access logs may be created automatically while you use the service.
2. Public information
To support the sharing features of the online judge, oj.uz makes usernames, profile solve and attempt counts, problem statistics and rankings, and the source code and judging results of public submissions available to other users. Email addresses, Auth0 identifiers, and connection data are not made public.
3. Disclosure to third parties
The Operator does not sell personal data and does not ordinarily disclose it to third parties. Disclosure may occur where required by law or a lawful request. The processors below provide services on the Operator's behalf and are not independent third-party recipients.
4. Processors and international transfers
International transfers are necessary processing or storage for the formation and performance of the service contract and are disclosed in this Policy under Article 28-8(1)(3)(a) of Korea's Personal Information Protection Act.
| Processor | Service, purpose, and data | Country, timing, and method | Retention |
|---|---|---|---|
| Cloudflare, Inc. dpo@cloudflare.com | Hosting, network security, D1 database, R2 file storage, Queues, logs, and Turnstile Data: service data and connection information described in this Policy | United States and countries in Cloudflare's global network Primary database: Western North America; files: Asia-Pacific Transferred over encrypted networks when requests are made or data is stored | Until deletion by the Operator. Workers logs: 7 days; Queues: 4 days; database recovery history: 30 days; temporary judging webhook files: 14 days |
| Okta, Inc. (Auth0 by Okta) privacy@okta.com | Registration, authentication, email verification, and account security Data: email, username, Auth0 identifier, credentials including password data, authentication and login records, and IP address | Japan (JP-1) and countries of Auth0 subprocessors Transferred over encrypted networks during registration and login | Until account deletion; authentication event logs: 1 day |
| Mailgun Technologies, Inc. (Sinch) dpo@sinch.com | Delivery of verification and password-reset email Data: recipient address, message subject, body and headers, and delivery and bounce data | United States Transferred over encrypted networks when email is sent | Messages: 3 days; delivery logs: 5 days; bounce and abuse suppression data: until deletion |
| Pusher Ltd. / MessageBird UK Ltd. privacy@bird.com | Real-time delivery of judging progress Data: IP address, User-Agent, site origin, submission channel identifier, judging status, execution time, memory usage, and WebSocket connection information | Japan (Tokyo) Transferred over an encrypted WebSocket connection when an active submission appears | Event content is not stored after relay; connection IP may be kept for up to 14 days when an error occurs |
You may refuse an international transfer by not registering or by stopping use of the relevant feature. Refusal may prevent use of authentication, email verification, submissions, judging, or real-time status updates.
5. Deletion
Personal data is deleted without undue delay when it is no longer needed or its retention period expires. Electronic data is deleted using methods intended to make recovery impracticable. Data removed from Cloudflare D1 may remain in disaster-recovery Time Travel history for up to 30 days.
6. Your rights
You or an authorized legal representative may request access, correction, deletion, suspension of processing, or withdrawal of consent. Send requests to privacy@oj.uz. The Operator may verify identity or authority before responding as required by law.
7. Cookies and automatic collection
- Login session cookie: maintains authentication, up to 1 day
- Language cookie: remembers your language, 30 days
- Temporary login cookies: deleted after the login flow
- Cloudflare Turnstile cookies: bot detection and site security
You may block cookies in your browser, but login and some features may stop working. Cloudflare Web Analytics measures page performance without cookies and does not track individual users.
8. Security measures
The Operator uses encryption in transit, access controls for administrators and service accounts, separate handling of secrets, least-privilege access, and log review to protect personal data.
9. Children's data
oj.uz does not collect age or date of birth during registration. A legal representative of a child under 14 may contact the privacy representative to exercise rights of access, correction, or deletion on the child's behalf.
10. Privacy representative and complaints
Representative: Suchan Park, operator of oj.uz
Email: privacy@oj.uz
In Korea, you may also contact the Privacy Infringement Report Center at 118 or the Personal Information Dispute Mediation Committee at 1833-6972.
11. Changes to this Policy
Changes will be announced on the website before they take effect. Material changes affecting user rights will be announced with reasonable advance notice.