How ROT5 Works
ROT5 applies a simple substitution to digits 0-9. Each digit moves forward by 5 positions with wraparound, so 0 maps to 5 and 9 maps to 4. Letters and punctuation stay unchanged.
ROT5 and ROT18
ROT5 is often paired with ROT13 in a combined scheme called ROT18. In ROT18, letters use ROT13 while digits use ROT5, allowing both alphabetic and numeric content to be obscured in one pass.
Common ROT5 Use Cases
ROT5 is useful for lightly obscuring phone numbers, identifiers, ZIP codes, and sample numeric data. It is a convenience transformation, not a security feature.
ROT5 Conversion Table
The mapping is straightforward: 0↔5, 1↔6, 2↔7, 3↔8, and 4↔9. Because the digit set has 10 characters and the shift is 5, ROT5 is perfectly self-inverse.