Master of Science thesis Fighting Spam

RSABlindingFactor bf = createBlindingFactor();
byte[] t = FileHandler.writeObject(ballot);
BlindFingerprint bfp = blind(publ, bf, Fingerprint.create(t, 0, t.length,
"SHA1"));
BlindSignature bs = blindSign(priv, bfp);
org.logi.crypto.sign.Signature signed = unblind(publ, bs, bf);
boolean ok = verify(publ, signed, ballot);
Debugger.debug(className, 3, "Verifying blind signature (true)? = " + ok); //must
return true
org.logi.crypto.sign.Signature signedNormal = sign(priv, ballot);
ok = equals(signed.getBytes(), signedNormal.getBytes());
Debugger.debug(className, 3, "Testing blind signature = signature (true)? = " +
ok); //must return true
ballot.setType(Coin.C_TYPE); //corrupting data
// ballot[0] = 4;
boolean ok2 = verify(publ, signed, ballot);
Debugger.debug(className, 3, "Testing blind signature functions completed
successful(false)? = " + ok2); //must return false
org.logi.crypto.sign.Signature signed2 = sign(priv, ballot);
boolean ok3 = verify(publ, signed2, ballot);
Debugger.debug(className, 3, "Testing blind signature functions completed
successful(true)? = " + ok3); //must return true
}
public static boolean equals(byte[] a, byte[] b)
{
if(a.length != b.length)
return false;
}
for(int i = 0; i < a.length; i++)
if(a[i] != b[i])
return false;
return true;
public static String hexDigit(byte x)
{
StringBuffer sb = new StringBuffer();
char c;
// First nibble
c = (char) ((x >> 4) & 0xf);
if(c > 9)
{
c = (char) ((c - 10) + 'a');
}
else
{
c = (char) (c + '0');
}
sb.append(c);
// Second nibble
c = (char) (x & 0xf);
if(c > 9)
{
c = (char) ((c - 10) + 'a');
}
else
{
c = (char) (c + '0');
}
sb.append(c);
return sb.toString();
}
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