A point of sale system comprising: a first discrete device with a first means for receiving first payment information; a second discrete device with a second means for receiving second payment information; a wire communicatively connecting the first discrete device to the second discrete device; a second memory system on the second discrete device having stored thereon a public key certificate and a corresponding private key; and a first memory system on the first discrete device that stores instructions to: (i) receive the public key certificate from the second discrete device; (ii) verify the public key certificate; and (iii) form a secure connection between the first discrete device and the second discrete device over the wire using a protocol after the public key certificate is verified; wherein to form the secure connection using the protocol, the first discrete device and the second discrete device conduct a handshake using a public key from the public key certificate and the corresponding private key; wherein the handshake comprises one of (a) a secret that is encrypted at the first discrete device using the public key from the public key certificate to generate an encrypted secret that is transmitted to the second discrete device, wherein the second discrete device decrypts the encrypted secret using the corresponding private key such that upon decryption, both the first discrete device and the second discrete device share the secret; or (b) a pre-master that is encrypted at the first discrete device using the public key from the public key certificate to generate an encrypted pre-master that is sent to the second discrete device, wherein the second discrete device decrypts the encrypted pre-master using the corresponding private key to generate a decrypted pre-master, and wherein the first discrete device and the second discrete device each generate a shared secret from the pre-master and the decrypted pre-master, respectively; wherein upon establishing the secure connection, the first discrete device transmits, via the secure connection, a copy of a first payment key set to the second discrete device and wherein the second discrete device generates a second payment key using the first payment key set; or wherein the first discrete device generates a first payment key using the first payment key set and upon establishing the secure connection, transmits, via the secure connection, a copy of the first payment key to the second discrete device. a first discrete device with a first means for receiving first payment information; a second discrete device with a second means for receiving second payment information; a wire communicatively connecting the first discrete device to the second discrete device; a second memory system on the second discrete device having stored thereon a public key certificate and a corresponding private key; and a first memory system on the first discrete device that stores instructions to: (i) receive the public key certificate from the second discrete device; (ii) verify the public key certificate; and (iii) form a secure connection between the first discrete device and the second discrete device over the wire using a protocol after the public key certificate is verified; wherein to form the secure connection using the protocol, the first discrete device and the second discrete device conduct a handshake using a public key from the public key certificate and the corresponding private key; wherein the handshake comprises one of (a) a secret that is encrypted at the first discrete device using the public key from the public key certificate to generate an encrypted secret that is transmitted to the second discrete device, wherein the second discrete device decrypts the encrypted secret using the corresponding private key such that upon decryption, both the first discrete device and the second discrete device share the secret; or (b) a pre-master that is encrypted at the first discrete device using the public key from the public key certificate to generate an encrypted pre-master that is sent to the second discrete device, wherein the second discrete device decrypts the encrypted pre-master using the corresponding private key to generate a decrypted pre-master, and wherein the first discrete device and the second discrete device each generate a shared secret from the pre-master and the decrypted pre-master, respectively; wherein upon establishing the secure connection, the first discrete device transmits, via the secure connection, a copy of a first payment key set to the second discrete device and wherein the second discrete device generates a second payment key using the first payment key set; or wherein the first discrete device generates a first payment key using the first payment key set and upon establishing the secure connection, transmits, via the secure connection, a copy of the first payment key to the second discrete device.