check signature mechanism

[lispc]

gates profile result of Block(4, 2, 2):

main.processTransfer.newSenderHash.hash.mimcs.invpow.pow5 1716.28
main.processTransfer.oldReceiverHash.hash.mimcs.invpow.pow5 1716.28
main.processTransfer.newReceiverHash.hash.mimcs.invpow.pow5 1716.28
main.processWithdraw.oldAccountHash.hash.mimcs.invpow.pow5 1716.28
main.processWithdraw.newAccountHash.hash.mimcs.invpow.pow5 1716.28
main.processDepositToNew.newAccountHash.hash.mimcs.invpow.pow5 1716.57
main.processTransfer.sigVerifier.mulFix.segments.adders 2354.35
main.processWithdraw.sigVerifier.mulFix.segments.adders 2354.35
main.processTransfer.sigVerifier.hash.mimcs.pow 2415.89
main.processWithdraw.sigVerifier.hash.mimcs.pow 2415.89
main.processTransfer.sigVerifier.hash.mimcs.invpow.pow5 2589.78
main.processWithdraw.sigVerifier.hash.mimcs.invpow.pow5 2589.78
main.processTransfer.sigVerifier.mulAny.segments.bits.selector 3870.84
main.processWithdraw.sigVerifier.mulAny.segments.bits.selector 3870.84
main.processTransfer.sigVerifier.mulFix.segments.windows.mux 4332.03
main.processWithdraw.sigVerifier.mulFix.segments.windows.mux 4332.03
main.processTransfer.sigVerifier.mulAny.segments.bits 5329.30
main.processWithdraw.sigVerifier.mulAny.segments.bits 5329.30
main.processTransfer.sigVerifier.mulAny.segments.bits.doubler 5440.06
main.processWithdraw.sigVerifier.mulAny.segments.bits.doubler 5440.06
main.processTransfer.sigVerifier.mulAny.segments.bits.adder 5616.06
main.processWithdraw.sigVerifier.mulAny.segments.bits.adder 5616.06
one 34781.95

total_gates 274159.00

TODO: check whether the gate cost of sigVerifier is reasonable.