The 3+4 split IS a signature scheme. 7 CRT channels split into 3 data channels {mod 8, mod 25, mod 49} (private) and 4 parity channels {mod 9, mod 11, mod 13, mod 17} (public verification). Sign with data channels. Verify with parity channels. 4 parity channels detect any tampering in the full 7-channel signature. The algebra IS the cryptography.
Message (any integer):
Private key mod 1680 (Carmichael period). Red = data channels (private). Green = parity channels (public verification).
Sign 100 messages with key=137. Verify all. Then tamper each and check rejection.
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