Cryptographic Primitives

• Hash Functions

• Commitment

trapdoor commitment scheme: allows a trapdoor holder to find a properly distributed opening randomness for the commitment.

decryptable commitment scheme, supporting a trapdoor decryption algorithm that enables the authority with some trapdoor to recover a message from a given commitment.

verifiable decryptable commitment allows protocol parties to verify that a commitment is decryptable by the authority,
while still hiding its contents from all other parties.

• blind signature

• group signature