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how to convert a elliptic point to a unique value?

ie using ECC for curve y2=x3+x+1 and p=23 i generated elliptic points and for a message, I mapped the characters of the message to elliptic points so computed.

Now i want to pass the set of points to another cryptographic algorithm say goldwasser inorder to perform encryption.

Is there any algorithm to convert the point to a integral value?

abhi
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1 Answers1

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Look for Elliptic Curve Point Compression.

In OpenSSL(which follows X9.62 standard), there are functions for this purpose:

  • BIGNUM *EC_POINT_point2bn() - convert EC point to bignum
  • char *EC_POINT_point2hex() - convert EC point to hex string

And ofcourse, functions to convert it back:

  • EC_POINT *EC_POINT_bn2point()
  • EC_POINT *EC_POINT_hex2point()

For JAVA, check out the answer of this post.

Community
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Chiara Hsieh
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