A cross-domain information transfer system comprising: a key distribution center configured to generate a plurality of private encryption keys, and a respective signature key pair for each attribute from among a plurality of different attributes, each attribute associated with a given domain among a plurality of different domains, and each signature key pair comprising a secret signing key and a secret verifying key; a sender device comprising a processor and a transceiver coupled thereto, and configured to receive a respective private encryption key and generate ciphertext from plaintext based upon the private encryption key, append a respective attribute for a given domain to the ciphertext, receive a respective secret signing key and generate ciphertext with a concealed attribute from the ciphertext with the appended attribute based upon the secret signing key, and broadcast the ciphertext with the concealed attribute through an untrusted network; and a plurality of domain gateway devices in communication with the untrusted network, wherein the plurality of different domains has different security levels associated therewith, each domain gateway device comprising a processor and a transceiver coupled thereto, and having a respective attribute associated therewith and configured to: receive a respective secret verifying key, receive the ciphertext with the concealed attribute from the untrusted network, and use the secret verifying key to determine if the concealed attribute matches the attribute associated with the domain gateway device, and, when so, pass the ciphertext to at least one receiver device coupled with the domain gateway device, wherein the at least one receiver device comprising a processor and a transceiver coupled thereto, is configured to decrypt the ciphertext into plaintext based upon the private encryption key. a key distribution center configured to generate a plurality of private encryption keys, and a respective signature key pair for each attribute from among a plurality of different attributes, each attribute associated with a given domain among a plurality of different domains, and each signature key pair comprising a secret signing key and a secret verifying key; a sender device comprising a processor and a transceiver coupled thereto, and configured to receive a respective private encryption key and generate ciphertext from plaintext based upon the private encryption key, append a respective attribute for a given domain to the ciphertext, receive a respective secret signing key and generate ciphertext with a concealed attribute from the ciphertext with the appended attribute based upon the secret signing key, and broadcast the ciphertext with the concealed attribute through an untrusted network; and a plurality of domain gateway devices in communication with the untrusted network, wherein the plurality of different domains has different security levels associated therewith, each domain gateway device comprising a processor and a transceiver coupled thereto, and having a respective attribute associated therewith and configured to: receive a respective secret verifying key, receive the ciphertext with the concealed attribute from the untrusted network, and use the secret verifying key to determine if the concealed attribute matches the attribute associated with the domain gateway device, and, when so, pass the ciphertext to at least one receiver device coupled with the domain gateway device, wherein the at least one receiver device comprising a processor and a transceiver coupled thereto, is configured to decrypt the ciphertext into plaintext based upon the private encryption key. receive a respective secret verifying key, receive the ciphertext with the concealed attribute from the untrusted network, and use the secret verifying key to determine if the concealed attribute matches the attribute associated with the domain gateway device, and, when so, pass the ciphertext to at least one receiver device coupled with the domain gateway device, wherein the at least one receiver device comprising a processor and a transceiver coupled thereto, is configured to decrypt the ciphertext into plaintext based upon the private encryption key.