Algorithm 3: Verification algorithm of data trading information traceability process

$\mathbf{Input}\mathbf{:} SupPeer$$, Ke{y}_{supcha}$$, Ke{y}_{oriinfo}$$, TradingName$    $\mathbf{Output}\mathbf{:} Veriresult$ $1 // \mathrm{Query} \mathrm{the} \mathrm{original} \mathrm{data} \mathrm{trading} \mathrm{information} \mathrm{and} \mathrm{its} \mathrm{corresponding} \mathrm{block} \mathrm{number} \mathrm{from} \mathrm{the} \mathrm{off}-\mathrm{chain} \mathrm{database}$ $2 OriTradingInfo=\mathrm{queryTradingInfo}(SupPeer$$, Ke{y}_{oriinfo}$$, TradingName);$ $3 // \mathrm{Compute} \mathrm{the} \mathrm{hash} \mathrm{value} \mathrm{of} \mathrm{the} \mathrm{original} \mathrm{data} \mathrm{trading} \mathrm{information}$ $4 H_1=\mathrm{calcHash}\left(OriTradingInfo\right);$ $5 // \mathrm{Query} \mathrm{the} \mathrm{hash} \mathrm{value} \mathrm{in} \mathrm{the} \mathrm{blockchain} \mathrm{based} \mathrm{on} \mathrm{the} \mathrm{block} \mathrm{number}$ $6 H_2=\mathrm{queryTradingInfo}(SupPeer$$, Ke{y}_{supchan}$$, OriTradingInfo\left[7\right]);$ $7 \mathbf{If} (H_1$$==H_2)$ $8 \mathrm{return} Veripass;$ $9 \mathrm{else}$ $10 \mathrm{return} Verifail$;