Customer Authentication System – SK Telecom

SK Telecom utilizes Altibase’s hybrid architecture for its authentication system. Altibase replaced Active Directory, Microsoft LDAP solution.

Use Case: IP Authentication

Current Customers: SK Telecom, KT and LG Uplus

Industry: Telecommunications


SK Telecom is the largest mobile service provider in South Korea with over 20 million subscribers. SK Telecom introduced the world’s first CDMA technology and was awarded for its leadership in LTE. Currently, SK Telecom is paving the way for LTE-advanced and 5G capabilities.[1]


SK Telecom had two issues using Active Directory server, Microsoft LDAP solution, for its customer authentication.

  • The authentication system became slow when there was an increase in the number of concurrent users. Its clients began to complain.
  • SK Telecom needed to replicate its data for backup. It took between four and five days to complete the replication of data for its 17 million customers.
  • SK Telecom was in dire need of databases to speed up the authentication process even when many users attempted to logon. The new databases should also be able to replicate data much more quickly.


SK Telecom has adopted Altibase for customer authentication system since 2005. In choosing Altibase, there was no benchmark testing for other databases because SK Telecom did not consider any other database vendors. SK Telecom was one of the first companies to adopt Altibase for its hybrid architecture which Altibase then began to feature. Altibase was the first company in the world to develop and commercialize a hybrid database in 2005.

With the hybrid architecture, user information is stored and manipulated in memory. After a certain lapse of time, cold or less frequently used data is transferred to and stored on disk. The net result is higher transaction performance of hot or more frequently used user information. The architecture has enabled SK Telecom to eliminate the need to purchase on-disk databases separately to store cold or less frequently used data, resulting in lower database-related TCO.


  • The authentication process became 4 times faster than that with Microsoft LDAP solution.
  • Its replication process now took two hours, down from four and five days. Its schema change work took only three hours, down from one month with LDAP.
  • SK Telecom took advantage of Altibase’s hybrid architecture by moving a substantial amount data (20G) between in-memory and on-disk tables when the move was necessary for different processing speeds.
  • The net result was much less use of CPU and system resources with 70% reduction in TCO.


[1] SK Telecom now has 53% of market share representing over 20 million subscribers.

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