Obviousness

To analyze the obviousness of US patent 11233780 under 35 U.S.C. § 103, we will consider the independent claims and combinations of prior art references cited within the patent itself. A person having ordinary skill in the art (PHOSITA) in 2013 (the priority date of the patent) would be knowledgeable in wireless communication technologies, network security, integrated circuit cards (UICC/SIM), embedded UICCs (eUICCs), and various authentication and key management protocols.

The prior art references used in this analysis are sourced from the "References Cited" section of US11233780 on Google Patents (https://patents.google.com/patent/US11233780/en).

Obviousness Analysis of Independent Claim 1 (Method for securing communications)

Claim 1 Elements and Prior Art Relevance:

1. Receiving an encrypted profile including a first ciphertext portion and a second ciphertext portion:

   • The general concept of an eUICC receiving an encrypted profile for remote provisioning is well-established in the prior art, as exemplified by US8635467B2 (Secured provisioning of UICC profile) and the requirements outlined in ETSI TS 103 383 v12.1 (Embedded UICC; Requirements Specification). A PHOSITA would recognize that dividing a profile into multiple encrypted portions (e.g., a "first ciphertext portion" and a "second ciphertext portion") is a routine design choice to implement layered security or staged access to different sets of credentials, depending on the desired level of authentication or trust.

2. Decrypting the first ciphertext portion using an eUICC profile key and a symmetric ciphering algorithm to obtain a plaintext first key (K) and a plaintext first network module identity:

   • ETSI TS 103 383 v12.1 details eUICC profiles containing network access credentials like a subscriber identity (network module identity) and a secret key K for network authentication. US8635467B2 teaches the secure provisioning of such profiles, inherently involving decryption using an appropriate key. Symmetric ciphering is a widely known and fundamental cryptographic technique for data decryption using a shared key. The patent itself notes a problem that the invention addresses: that the security of an electronically transferred key K is dependent on the encryption of the channel and the security of keys used for that channel, which may be outside MNO control.

3. Performing a first authentication with a wireless network using the plaintext first key and the plaintext first network module identity:

   • This step describes a standard mobile network authentication process. 3GPP TS 33.401 V12.9.0 (3GPP System Architecture Evolution (SAE); Security architecture) and ETSI TR 102 216 V11.0.0 (UICC; Physical and logical characteristics) define the challenge-response authentication mechanism (e.g., using RAND and RES values with a pre-shared secret key K) for mobile devices accessing wireless networks (e.g., 3G, 4G LTE). The patent acknowledges this as a "core element of traditional wireless WAN technologies." US8219792B2 (M2M services using virtual SIM) would implicitly require this standard authentication for virtual SIMs (eUICCs) to function.

4. Performing a second authentication with a mobile network operator (MNO) using a second factor over the wireless network:

   • The general concept of two-factor authentication (2FA) for verifying user or device identity is a well-known security practice, separate from the initial network attachment. It involves combining two different authentication factors (e.g., something the user knows, something the user has, or something the user is). The patent describes examples of this second authentication as a user entering information on a web page or making a telephone call to a call center to confirm identity. The patent also explicitly states the problem that "a need exists in the art for the MNO to securely and efficiently control the use of an electronically transferred key K within a profile for an eUICC, even though copying and distributing the profile may be outside the control of the MNO."

5. Receiving a symmetric key from the MNO subsequent to a successful second authentication:

   • The secure transmission of configuration data and keys from an MNO or subscription manager to a device is inherent in remote provisioning systems (e.g., US8635467B2, US8948756B2 - Over-the-air provisioning of SIM profiles).

6. Using the received symmetric key to decrypt the second ciphertext portion of the encrypted profile to reveal a plaintext second key (K) and a plaintext second network module identity:

   • This is a continuation of the decryption process, similar to the first decryption step, but utilizing a newly received key. The concept of using different keys for different portions of an encrypted profile, or for different stages of access, is a predictable application of cryptographic principles. The patent highlights the desirability for MNOs to "periodically rotate or change" key K for increased security, and that "the continued and extended use of a single key K...can be a security risk."

Motivation to Combine for Claim 1:
A PHOSITA would be motivated to combine ETSI TS 103 383 v12.1 (eUICC requirements), US8635467B2 (secured provisioning of UICC profile), and 3GPP TS 33.401 V12.9.0 (SAE security architecture), along with general knowledge of multi-factor authentication, to address the known problem of MNO control and enhanced security for eUICC profiles.

Given that eUICC profiles contain critical network access credentials (ETSI TS 103 383) and can be remotely provisioned (US8635467B2), a PHOSITA would recognize that the initial provisioning, especially through potentially untrusted channels, might not provide sufficient assurance for the MNO. The explicit problem stated in the patent—the MNO's lack of control over key K distribution when the profile is copied or distributed—would drive a PHOSITA to devise a mechanism for the MNO to assert control over the most secure credentials.

It would be obvious to:

• Allow initial network access using a first set of credentials (which might be less secure, temporary, or even a null key as discussed in the patent) to establish a basic communication channel. This initial authentication is standard practice for mobile networks (3GPP TS 33.401).
• Implement a secondary, MNO-controlled authentication (a "second factor") over this established channel to verify the user or device association. Multi-factor authentication is a common security paradigm.
• Once this higher level of trust is established, the MNO would then provision the more sensitive, long-term, or regularly rotated keys. This would naturally involve sending a key to unlock the remaining, most critical, parts of the eUICC profile.
• Dividing the eUICC profile into two encrypted portions, with the second portion only decryptable after the MNO's second authentication, is a straightforward way to implement this staged release of credentials. This addresses the MNO's need for control and enhanced security, as the final, fully secure keys are only activated after direct MNO verification. This combination of known elements and principles would lead to the claimed method as a predictable improvement to existing secure eUICC provisioning, achieving the desired security and control benefits.

Obviousness Analysis of Independent Claim 11 (Module for securing communications)

Claim 11 Elements and Prior Art Relevance:

1. A physical interface configured to communicate with a wireless network:

   • This is a standard component of any mobile or M2M module. US8219792B2 (M2M services using virtual SIM) describes such a module with a physical interface for wireless communication.

2. A nonvolatile memory configured to store an embedded universal integrated circuit card (eUICC) and an encrypted profile, wherein the encrypted profile includes a first ciphertext portion and a second ciphertext portion:

   • Storing an eUICC in nonvolatile memory is a fundamental requirement for eUICC functionality and persistence, as specified in ETSI TS 103 383 v12.1 and exemplified by US9806950B2 (Embedded SIM with secure element), which describes secure elements typically implemented with nonvolatile memory. The storage of an "encrypted profile" is taught by US8635467B2 (Secured provisioning of UICC profile). As discussed for Claim 1, structuring the profile into two ciphertext portions is a logical design choice for implementing staged access to credentials.

3. A central processing unit (CPU) coupled to the physical interface and the nonvolatile memory, the CPU configured to perform the steps of Claim 1:

   • A CPU is a standard component of any module or device (US8219792B2, US9806950B2). Configuring a CPU to execute a sequence of operations, including cryptographic functions (decryption, key management) and communication protocols (network authentication, 2FA interaction), is a routine task for a PHOSITA. The functional configuration of the CPU to perform the method steps of Claim 1 (which are themselves obvious) would thus be an obvious implementation.

Motivation to Combine for Claim 11:
A PHOSITA would be motivated to combine US8219792B2 (M2M virtual SIM module) with US9806950B2 (embedded SIM with secure element), and general engineering knowledge of implementing cryptographic and communication functions within a module, to create a device capable of executing the security method described in Claim 1.

Given the existence of modules designed for M2M communications with virtual SIM capabilities (US8219792B2), and the knowledge that eUICCs are typically stored in secure elements with nonvolatile memory (US9806950B2), it would be an obvious engineering task to configure such a module's CPU to perform the steps of the two-factor authentication and staged key provisioning method (as described in Claim 1). The specific arrangement of nonvolatile memory to store a profile in two ciphertext portions for sequential decryption, driven by the need for enhanced MNO control and security, is a predictable architectural choice for a PHOSITA designing a robust eUICC system.

Obviousness Analysis of Independent Claim 15 (Method for securing eUICC profile key)

Claim 15 Elements and Prior Art Relevance:

1. Sending, by a module, an embedded universal integrated circuit card (eUICC) identity to an eUICC subscription manager through a first network:

   • The concept of an eUICC communicating its identity to an eUICC subscription manager for provisioning is fundamental to ETSI TS 103 383 v12.1. The "first network" (e.g., WiFi, wired connection, or another mobile network) for initial provisioning is explicitly mentioned in the patent as a known alternative to the target wireless network.

2. Receiving, by the module, an encrypted eUICC profile key, wherein the eUICC profile key is encrypted with an asymmetric ciphering algorithm and an eUICC public key:

   • The patent states that "the eUICC can record an eUICC private key and the eUICC subscription manager could record an eUICC public key", indicating a Public Key Infrastructure (PKI) setup. The use of asymmetric cryptography (PKI) for securely exchanging or distributing keys is a well-established and fundamental security practice. US9077651B2 (System and method for providing security keys) and US8533470B2 (Method for generating a key for authentication and encryption) broadly cover key provision, and a PHOSITA would know PKI as a primary method for securing such transfers in an untrusted environment.

3. Decrypting, by the module, the encrypted eUICC profile key using the asymmetric ciphering algorithm and an eUICC private key to obtain a plaintext eUICC profile key:

   • This is the standard, complementary step to asymmetric encryption, where the corresponding private key decrypts data encrypted with the public key.

4. Receiving, by the module, an encrypted profile, wherein the encrypted profile is encrypted with the plaintext eUICC profile key and a symmetric ciphering algorithm:

   • Receiving an encrypted profile is known from US8635467B2 and ETSI TS 103 383 v12.1. Encrypting the profile data itself with a symmetric key (the "eUICC profile key") is a common and efficient method for bulk data encryption, as noted in the patent ("the eUICC subscription manager 109 can use an eUICC profile key 107 b to cipher portions of an eUICC profile 107 c, such that only module 101 with the same eUICC profile key 107 b could reasonably decipher the portions of the eUICC profile 107 c.")

5. Decrypting, by the module, the encrypted profile using the plaintext eUICC profile key and the symmetric ciphering algorithm to extract a plaintext first key (K) and a plaintext first network module identity:

   • This is a standard decryption step using the symmetric eUICC profile key.

6. Using the plaintext first key and the plaintext first network module identity to perform a first authentication with a wireless network:

   • As discussed for Claim 1, this is a standard mobile network authentication process, well-known in the prior art (3GPP TS 33.401, ETSI TR 102 216).

Motivation to Combine for Claim 15:
A PHOSITA would be motivated to combine ETSI TS 103 383 v12.1 (eUICC requirements and provisioning), US8635467B2 (secured provisioning of UICC profile), and general knowledge of Public Key Infrastructure (PKI) and asymmetric/symmetric cryptography, to achieve secure provisioning of eUICC profiles.

Given the necessity of securely transferring sensitive eUICC profiles and their associated keys to a module, a PHOSITA would recognize the limitations of simple channel encryption or pre-shared symmetric keys for initial provisioning, especially when dealing with potentially untrusted distribution channels or initial network connections. Therefore, it would be obvious to employ the well-known principles of PKI for secure key establishment. Specifically, using asymmetric encryption (public/private key pair) to securely transmit the symmetric "eUICC profile key" that then decrypts the larger, symmetrically encrypted eUICC profile (containing the first key K and network module identity) is a fundamental and common approach in secure communications. This layered encryption strategy (asymmetric for key transport, symmetric for bulk data encryption) is a predictable and effective way for a PHOSITA to ensure the confidentiality and integrity of eUICC profile provisioning, as required by eUICC standards (ETSI TS 103 383) and prior art on secure provisioning (US8635467B2).