# derby.authentication.builtin.iterations

The derby.authentication.builtin.iterations property specifies the number of times to apply the hash function (which is specified by the derby.authentication.builtin.algorithm property) on the credentials.

Iteration slows down attackers by forcing them to spend more time calculating hashes. See derby.authentication.builtin.algorithm for more information.

This property is in effect only if NATIVE authentication is specified by the derby.authentication.provider property and if the derby.authentication.builtin.algorithm property has a non-null value.

## Syntax

    derby.authentication.builtin.iteration=number_of_iterations

The minimum value is 1.

## Default

1000.

## Example

    -- system-wide property
    derby.authentication.builtin.iterations=2000

    -- database-level property
    CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY(
        'derby.authentication.builtin.iterations', '2000');

## Dynamic or static

Dynamic; the change takes effect immediately. For information about dynamic changes to properties, see Dynamic and static properties.

Parent topic: Derby properties
Related reference
derby.authentication.builtin.algorithm
derby.authentication.builtin.saltLength
derby.authentication.ldap.searchAuthDN
derby.authentication.ldap.searchAuthPW
derby.authentication.ldap.searchBase
derby.authentication.ldap.searchFilter
derby.authentication.native.passwordLifetimeMillis
derby.authentication.native.passwordLifetimeThreshold
derby.authentication.provider
derby.authentication.server
derby.connection.requireAuthentication
derby.database.classpath
derby.database.defaultConnectionMode
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derby.database.fullAccessUsers
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derby.database.propertiesOnly
derby.database.readOnlyAccessUsers
derby.database.sqlAuthorization
derby.infolog.append
derby.jdbc.xaTransactionTimeout
derby.language.logQueryPlan
derby.language.logStatementText
derby.language.sequence.preallocator
derby.language.statementCacheSize
derby.locks.deadlockTimeout
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derby.locks.escalationThreshold
derby.locks.monitor
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derby.replication.logBufferSize
derby.replication.maxLogShippingInterval
derby.replication.minLogShippingInterval
derby.replication.verbose
derby.storage.indexStats.auto
derby.storage.indexStats.log
derby.storage.indexStats.trace
derby.storage.initialPages
derby.storage.minimumRecordSize
derby.storage.pageCacheSize
derby.storage.pageReservedSpace
derby.storage.pageSize
derby.storage.rowLocking
derby.storage.tempDirectory
derby.storage.useDefaultFilePermissions
derby.stream.error.extendedDiagSeverityLevel
derby.stream.error.field
derby.stream.error.file
derby.stream.error.logBootTrace
derby.stream.error.logSeverityLevel
derby.stream.error.method
derby.stream.error.rollingFile.count
derby.stream.error.rollingFile.limit
derby.stream.error.rollingFile.pattern
derby.stream.error.style
derby.system.bootAll
derby.system.durability
derby.system.home
derby.user.UserName
DataDictionaryVersion