Java tutorial
package org.bouncycastle.crypto.digests; /** * Encodable digests allow you to download an encoded copy of their internal state. This is useful for the situation where * you need to generate a signature on an external device and it allows for "sign with last round", so a copy of the * internal state of the digest, plus the last few blocks of the message are all that needs to be sent, rather than the * entire message. */ public interface EncodableDigest { /** * Return an encoded byte array for the digest's internal state * * @return an encoding of the digests internal state. */ byte[] getEncodedState(); }