A method for validating cryptographically signed records, the method comprising: under control of a hardware processor: receiving, at a record receiver device, a sender individual record from a record sender device, wherein: the sender individual record comprises a record identifier, a record content, a sender public key, a receiver public key of the record receiver device, and a sender signature of the sender individual record, wherein the record identifier of the sender individual record is a monotonically increasing number, and the sender individual record is created by the record sender device after receiving a content request from the record receiver device and after the record sender device identifies the record receiver device; maintaining, at the record receiver device, a highest record identifier associated with sender individual records previously received from the record sender device, wherein the record receiver device maintains the highest record identifier of individual records previously received with the sender public key of the record sender device as sender public keys of the individual records previously received; attempting to decrypt the sender signature by using the sender public key; detecting mousing by determining, via the record receiver device, that the sender individual record is invalid based at least in part on a failed attempt to decrypt the sender signature using the sender public key, wherein determining that the sender individual record is invalid comprises detecting sender cloning with a single receiver, wherein detecting sender cloning comprises determining the record identifier of the sender individual record is not larger than the highest record identifier; creating a receiver individual record, wherein: the receiver individual record comprises the sender individual record, and a receiver signature of the receiver individual record, and the receiver signature is created using a receiver private key of the record receiver device, and wherein the receiver public key and the receiver private key form a receiver public-key cryptographic pair; and sending the receiver individual record to the processing platform. the sender individual record comprises a record identifier, a record content, a sender public key, a receiver public key of the record receiver device, and a sender signature of the sender individual record, wherein the record identifier of the sender individual record is a monotonically increasing number, and the sender individual record is created by the record sender device after receiving a content request from the record receiver device and after the record sender device identifies the record receiver device; maintaining, at the record receiver device, a highest record identifier associated with sender individual records previously received from the record sender device, wherein the record receiver device maintains the highest record identifier of individual records previously received with the sender public key of the record sender device as sender public keys of the individual records previously received; attempting to decrypt the sender signature by using the sender public key; detecting mousing by determining, via the record receiver device, that the sender individual record is invalid based at least in part on a failed attempt to decrypt the sender signature using the sender public key, wherein determining that the sender individual record is invalid comprises detecting sender cloning with a single receiver, wherein detecting sender cloning comprises determining the record identifier of the sender individual record is not larger than the highest record identifier; creating a receiver individual record, wherein: the receiver individual record comprises the sender individual record, and a receiver signature of the receiver individual record, and the receiver signature is created using a receiver private key of the record receiver device, and wherein the receiver public key and the receiver private key form a receiver public-key cryptographic pair; and sending the receiver individual record to the processing platform. the receiver individual record comprises the sender individual record, and a receiver signature of the receiver individual record, and the receiver signature is created using a receiver private key of the record receiver device, and wherein the receiver public key and the receiver private key form a receiver public-key cryptographic pair; and sending the receiver individual record to the processing platform.