Method and device for processing service

The invention provides a method and a device for processing service. The service processing method comprises steps: an original card number for requesting service processing is received; according to the original card number, a hash value corresponding to the original card number is calculated, and an index card number corresponding to the original card number is acquired according to the hash value corresponding to the original card number; and the index card number is sent to an entity for processing the service to enable the entity to process the service according to the index card number. Corresponding index card numbers are built for a large amount of original card numbers in the system respectively, absolute one-to-one correspondence between the index card numbers and the original card numbers can be ensured under high concurrency, and search convenience in conditions in which a credit card number is encrypted and passwords are changed frequently can be ensured.