A method for use in cryptographic operations to prevent theft of encryption keys in payment processing, comprising: splitting , at a key broker server , a key that is used in a cryptographic operation into a first portion and a second portion, wherein a remote transaction using a client device of a user uses the cryptographic operation and wherein the remote transaction is between the user and a merchant via a merchant application ; storing , by one or more data processors, the first portion of the key; receiving , at the key broker server from the user , a remote request from the client device for retrieval of the first portion of the key corresponding to the second portion of the key; in response to receiving the remote request, performing , at a key broker system on the key broker server , a security analysis upon the remote request according to a security analysis criteria, wherein the security analysis criteria includes whether the key has been involved in a known breach; and transmitting the first portion of the key from the key broker system on the key broker server to the client device of the user after the security analysis criteria have been satisfied; wherein the client device of the user receives the first portion of the key and reconstitutes the key by combining the first portion of the key with the second portion of the key; and wherein the reconstituted key is only available to the client device provided the remote request meets the security analysis criteria and the first portion of the key is provided to the client device of the user such that a key involved in a known breach cannot be retrieved, wherein the client device of the user uses the reconstituted key to complete the remote transaction at the client device of the user . splitting , at a key broker server , a key that is used in a cryptographic operation into a first portion and a second portion, wherein a remote transaction using a client device of a user uses the cryptographic operation and wherein the remote transaction is between the user and a merchant via a merchant application ; storing , by one or more data processors, the first portion of the key; receiving , at the key broker server from the user , a remote request from the client device for retrieval of the first portion of the key corresponding to the second portion of the key; in response to receiving the remote request, performing , at a key broker system on the key broker server , a security analysis upon the remote request according to a security analysis criteria, wherein the security analysis criteria includes whether the key has been involved in a known breach; and transmitting the first portion of the key from the key broker system on the key broker server to the client device of the user after the security analysis criteria have been satisfied; wherein the client device of the user receives the first portion of the key and reconstitutes the key by combining the first portion of the key with the second portion of the key; and wherein the reconstituted key is only available to the client device provided the remote request meets the security analysis criteria and the first portion of the key is provided to the client device of the user such that a key involved in a known breach cannot be retrieved, wherein the client device of the user uses the reconstituted key to complete the remote transaction at the client device of the user . <EOS>