Field Hasher

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Description

The Field Hasher processor is a data transformation component that applies cryptographic hash functions to string values in a data stream. It can be used to encode sensitive information, generate unique identifiers, or transform data for privacy and security purposes.

The processor supports three widely-used hash algorithms:

• MD5 - A 128-bit hash function
• SHA1 - A 160-bit hash function
• SHA2 - A 256-bit hash function (SHA-256 implementation)

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Required input

This processor requires an event stream that contains at least one field of type string. The string field will be used as input for the hash function.

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Configuration

Field

Specifies the string field that will be encoded. This field must exist in the input event stream and must contain string values.

Hash Algorithm

Select the hash algorithm to use for encoding the string field. Available options are:

• SHA1 - Produces a 40-character hexadecimal hash
• SHA2 - Produces a 64-character hexadecimal hash
• MD5 - Produces a 32-character hexadecimal hash

Output

The processor modifies the input event by replacing the value of the selected field with its hashed version. All other fields in the event remain unchanged.

Example

Input Event

{
  "timestamp": 1617183834000,
  "sensorId": "sensor123",
  "value": 42.5,
  "user": "john.doe@example.com"
}

Configuration

• Field: user
• Hash Algorithm: MD5

Output Event

{
  "timestamp": 1617183834000,
  "sensorId": "sensor123",
  "value": 42.5,
  "user": "e87f955d3b3499b8b13e901fd61b6b64"
}

Use Cases

1. Privacy Protection: Hash personally identifiable information (PII) before storage or transmission
2. Data Anonymization: Create anonymous identifiers from user data
3. Checksum Generation: Generate checksums for data validation
4. Unique ID Creation: Create unique identifiers from combinations of fields

Notes

• The hash functions are one-way transformations - the original value cannot be recovered from the hash
• The same input will always produce the same hash value
• Different hash algorithms provide different levels of collision resistance and output lengths
• For security-critical applications, consider using SHA2 as it provides stronger cryptographic properties