Converting text to point in ECC
I’m now building some simple codes for converting plain text character to a point on an elliptic curve.
Here’s how I’m gonna do it, based on Mike Rosing’s hints:
- Take the data, and treat it as an x value
- If x value fit on the curve, then find y. Each x value has two y values associated with it.
- If x value does not fit on the curve, add extra bits to the data (but make sure not to mess with the raw data)
- Check again
- Repeat until the combination of the raw data and extra bits does fit on the curve.
To get the x value back, just mask off the extra bits to recover the raw data.
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