# derby.authentication.builtin.saltLength

The derby.authentication.builtin.saltLength property specifies the number of bytes of random salt that will be added to users' credentials before hashing them.

Random salt has the effect of making it difficult for attackers to decode passwords by constructing rainbow tables.

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.saltLength=number_of_bytes

## Default

16.

## Example

    -- system-wide property
    derby.authentication.builtin.saltLength=32

    -- database-level property
    CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY(
        'derby.authentication.builtin.saltLength', '32');

## 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
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derby.authentication.builtin.algorithm
derby.authentication.builtin.iterations
derby.authentication.ldap.searchAuthDN
derby.authentication.ldap.searchAuthPW
derby.authentication.ldap.searchBase
derby.authentication.ldap.searchFilter
derby.authentication.native.passwordLifetimeMillis
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derby.authentication.provider
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derby.database.propertiesOnly
derby.database.readOnlyAccessUsers
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derby.infolog.append
derby.jdbc.xaTransactionTimeout
derby.language.logQueryPlan
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derby.locks.deadlockTimeout
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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
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derby.user.UserName
DataDictionaryVersion