An information processing apparatus comprising: processing circuitry configured to: retrieve, from a peer-to-peer network using an address generated from a first public key, a test score of a user, wherein the first public key is generated from a first secret key, decrypt the test score using a second secret key corresponding to a second public key used to encrypt the test score, calculate an evaluation score of the user based on the retrieved test score, retrieve, from the peer-to-peer network, supplemental data which indicate a same kind of detection result based on detected data of a plurality of different sensors or devices, and which further indicate a state or environment of the user when the user takes a test associated with the test score, and determine that the evaluation score is not legitimate, in case the detection result is equal to or greater than a threshold, or in case the detection results acquired from two different sensors or devices indicating the same kind of detection result considerably deviate from each other, wherein the test score is included in one or more transactions in blockchain data, the address is used to identify the one or more transactions to retrieve the test score, and one or more blocks of data including the transactions is circulated on the peer-to-peer network. processing circuitry configured to: retrieve, from a peer-to-peer network using an address generated from a first public key, a test score of a user, wherein the first public key is generated from a first secret key, decrypt the test score using a second secret key corresponding to a second public key used to encrypt the test score, calculate an evaluation score of the user based on the retrieved test score, retrieve, from the peer-to-peer network, supplemental data which indicate a same kind of detection result based on detected data of a plurality of different sensors or devices, and which further indicate a state or environment of the user when the user takes a test associated with the test score, and determine that the evaluation score is not legitimate, in case the detection result is equal to or greater than a threshold, or in case the detection results acquired from two different sensors or devices indicating the same kind of detection result considerably deviate from each other, retrieve, from a peer-to-peer network using an address generated from a first public key, a test score of a user, wherein the first public key is generated from a first secret key, decrypt the test score using a second secret key corresponding to a second public key used to encrypt the test score, calculate an evaluation score of the user based on the retrieved test score, retrieve, from the peer-to-peer network, supplemental data which indicate a same kind of detection result based on detected data of a plurality of different sensors or devices, and which further indicate a state or environment of the user when the user takes a test associated with the test score, and determine that the evaluation score is not legitimate, in case the detection result is equal to or greater than a threshold, or in case the detection results acquired from two different sensors or devices indicating the same kind of detection result considerably deviate from each other, wherein the test score is included in one or more transactions in blockchain data, the address is used to identify the one or more transactions to retrieve the test score, and one or more blocks of data including the transactions is circulated on the peer-to-peer network. <EOS>