| CPC H04L 9/005 (2013.01) [H04L 9/3218 (2013.01)] | 16 Claims |

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1. A messaging system secure against attacks of unbounded polynomial size, the system comprising:
a transmitter data store for storing an original message;
an encoder module configured for creating a non-malleable copy of the original message by:
generating a time-lock puzzle Z, the time-lock puzzle Z having hardness T, and being based on the original message;
generating a non-malleable commitment c, based on the original message;
generating a proof pi as a zero-knowledge proof of consistency between Z and c;
storing Z, c, and pi in the transmitter data store as the non-malleable copy of the original message;
a transmitter module configured for transmitting the non-malleable copy of the original message to a receiver; and
a decoder module at the receiver, the decoder module configured for decoding the non-malleable copy of the original message by:
verifying the proof pi;
when the proof pi is verified:
solving the time-lock puzzle Z and generating the original message as an output; and
storing the original message in a receiver data store.
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