XOR Byte Checksum

Compute explicit xorByteChecksum over caller bytes, bounded4096 bytes and no text encoding ambiguity; noncryptographic checksum does not establish authenticity.

Description

An XOR checksum combines byte values with bitwise exclusive-or.

An XOR checksum combines byte values with bitwise exclusive-or.^[1]

It can help compare simple data changes but is not a cryptographic integrity or authentication mechanism. Use XOR Byte Checksum to evaluate the supplied inputs under the specific model below.

When to use XOR Byte Checksum

Use XOR Byte Checksum to evaluate the supplied inputs under the specific model below. Choose the intended encoding, alphabet or check and keep the exact character, key and measurement conventions described below.

How to use XOR Byte Checksum and understand its results

Choose the intended encoding, alphabet or check and keep the exact character, key and measurement conventions described below.
Enter Byte values using the field table and validation rules below, then run the tool.
Read Xor byte checksum and interpret units, signs, ordering and placeholders as explained below.
If the tool reports an input error, correct that field and rerun. A successful false result, empty match list or unknown-evidence placeholder has the specific meaning described here; check the limitations before applying the result.

Input field	Meaning	Value type	Requirement
byteValues	Byte values	array of number	Required; constraints below

Enter a nonempty array of at most 4096 integer byte values from 0 to 255. Fold them with bitwise XOR starting at zero and return the byte checksum. Order permutations preserve the checksum and many different inputs collide; this is not a cryptographic hash or an integrity authentication mechanism.

checksum = byte[0] XOR byte[1] XOR …, with initial accumulator 0

Field order, units and branch conditions follow the implementation explanation above.

Output field	Meaning	Value type
xorByteChecksum	Xor byte checksum	number

json

{
  "input": {
    "byteValues": [
      1,
      2,
      3
    ]
  },
  "output": {
    "xorByteChecksum": 0
  }
}

Limitations and assumptions

It can help compare simple data changes but is not a cryptographic integrity or authentication mechanism. Apply the exact scope and assumptions described above.

All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are stated above; extremely large inputs or outputs can also be rejected. These errors differ from successful results such as false, no matches or unknown evidence.

Alternative or Complementary methods

Use BSD Sum Checksum for a related task: A BSD sum rotates a sixteen-bit accumulator before adding each byte.

Use SysV Checksum for a related task: A System V sum folds a byte total into a sixteen-bit value.

References

XOR Byte Checksum — tool.io

Similar or alternative tools

BSD Sum Checksum
A BSD sum rotates a sixteen-bit accumulator before adding each byte.
SysV Checksum
A System V sum folds a byte total into a sixteen-bit value.