/* Decrypts a "chunk" (a small part of a message) using "key" */
string RSA::decryptChunk(const BigInt &chunk, const Key &key)
{
BigInt a = chunk;
// The RSA decryption algorithm is a congruence equation.
a.SetPowerMod(key.GetExponent(), key.GetModulus());
// Decode the message to a readable form.
return RSA::decode(a);
}
/* Encrypts a "chunk" (a small part of a message) using "key" */
string RSA::encryptChunk(const string &chunk, const Key &key)
{
// First encode the chunk, to make sure it is represented as an integer.
BigInt a = RSA::encode(chunk);
// The RSA encryption algorithm is a congruence equation.
a.SetPowerMod(key.GetExponent(), key.GetModulus());
return a.ToString();
}