This document includes techniques, apparatuses, and systems related to an interface for revision-limited memory, which can improve various computing aspects and performance. In aspects, confidentiality, integrity, and availability may be ensured while increasing the performance of revision-limited memory. In this example, the techniques also enable the digital computing device to interact with information related to the revision-limited memory.

Systems, and associated methods, involving both a trusted and an untrusted device where sensitive data or keys are shared between those devices are disclosed. A disclosed method includes storing a key in a secure memory on a first device, receiving sensitive data via a user interface on a second device, generating a set of white box encryption instructions based on the key using a white box encryption generator on the first device, generating a complete data representation of the set of white box encryption instructions using a secure processor on the first device, transmitting the complete data representation from the first device to the second device, and encrypting the sensitive data using the complete data representation on the second device. The complete data representation is not Turing complete and is not executable with respect to the second device.

In one embodiment, a processing device includes a symmetric block cipher configured to encrypt plaintext blocks yielding respective ciphertext blocks, obfuscation circuitry configured to obfuscate the respective ciphertext blocks responsively to an obfuscation secret yielding respective obfuscated ciphertext blocks and an interface to send the respective obfuscated ciphertext blocks to at least one remote processing device. In one embodiment, the processing device provides side-channel attack protection within a symmetric key scheme by data obfuscation and by changing encryption/decryption keys using key manipulation so that different blocks or group of blocks of data are encrypted/decrypted using respective encryption/decryption keys.

A Physical Unclonable Function (PUF) based true random number generator (TRNG), a method for generating true random numbers, and an associated electronic device are provided. The PUF based TRNG may include a first obfuscation circuit, a cryptography circuit coupled to the first obfuscation circuit, and a second obfuscation circuit coupled to the cryptography circuit. The first obfuscation circuit obtains a first PUF value from a PUF pool of the electronic device, and performs a first obfuscation function on a preliminary seed based on the first PUF value to generate a final seed. The cryptography circuit utilizes the final seed as a key of a cryptography function to generate preliminary random numbers. The second obfuscation circuit obtains a second PUF value from the PUF pool, and performs a second obfuscation function on the preliminary random numbers based on the second PUF value to generate final random numbers.

Methods and systems are disclosed. At a respective computing system, a request to run a program on first data stored within the respective computing system may be received. In some examples, the first data may be stored in association with a data access policy that defines access restrictions for the first data. In response to receiving the request, whether the request to run the program on the first data satisfies the access restrictions defined by the data access policy may be determined. In response to determining whether the request to run the program satisfies the access restrictions, in accordance with a determination that the access restrictions are satisfied, the program may be run, including performing one or more operations on the first data in an environment within the respective computing system, where a contents of the environment cannot be accessed from outside of the environment.

A method for performing an elliptic curve cryptographic process to generate output data based on input data, the elliptic curve cryptographic process based on an elliptic curve over a finite field, wherein the generation of the output data comprises generating, based on a predetermined point V of the elliptic curve and a positive R-bit integer k, a first point of the elliptic curve that is based, at least in part, on the point kV of the elliptic curve, wherein k=Σ.sub.r=0.sup.R−1 2.sup.rb.sub.r and, for each r=0,1, . . . , R−1, b.sub.r is the bit value of k at bit position r of k, wherein the method comprises: storing, according to a partition of the R bit positions for k into T groups of bit positions P.sub.t (t=0, 1, . . . , T−1), a corresponding lookup table L.sub.t having, for each of the 2.sup.|P.sup.t.sup.|possible options for assigning to the |P.sub.t| bit positions s ∈ P.sub.t a respective bit value x.sub.s, a corresponding point of the elliptic curve that is based, at least in part, on the point (Σ.sub.s∈P.sub.t2.sup.sx.sub.s)V of the elliptic curve; obtaining k; and determining the first point as Σ.sub.t=0.sup.T−1l.sub.t, where l.sub.t is the point of the elliptic curve that corresponds, in lookup table L.sub.t, to the option for assigning to the |P.sub.t| bit positions s ∈ P.sub.t the corresponding bit value b.sub.s.

A method of performing a cryptographic process in a secured manner, wherein the cryptographic process generates output data based on input data, the generating of the output data involving generating a value y based on an amount of data x, the value y representing a combination, according to a linear transformation L, of respective outputs from a plurality of S-boxes S.sub.n (n=0, . . . , N−1) for integer N>1, wherein each S-box S.sub.n (n=0, . . . , N−1) implements a respective function H.sub.n that is either (a) the composition of a respective first function F.sub.n and a respective linear or affine second function G.sub.n so that H.sub.n=G.sub.n∘F.sub.n, or (b) the composition of a respective first function F.sub.n, a respective linear or affine second function G.sub.n and a respective third function W.sub.n so that H.sub.n=G.sub.n∘F.sub.n∘W.sub.n, wherein the method comprises: performing a first processing stage and a second processing stage to generate the value y based on the amount of data x, wherein: the first processing stage uses a plurality of first lookup tables to generate respective outputs, each output being based on at least part of the amount of data x, wherein, for each S-box S.sub.n (n=0, . . . , N−1), the respective first function F.sub.n is implemented by a corresponding first lookup table; and the second processing stage combines outputs from a plurality of second lookup tables to generate the value y, wherein the input to each second lookup table is formed from the output of a plurality of the first lookup tables, and wherein the set of second lookup tables is based on the second functions G.sub.n (n=0, . . . , N−1) and the linear transformation L.

Disclosed techniques relate to storing a key cache within a secure enclave. In some embodiments, a computing system receives, from an application, a request to access a database, where the request is associated with a particular account. The computing system then accesses, using an identifier associated with the particular account, a key cache stored in a secure enclave of a memory of the computing system to determine at least one private key associated with the request, where the key cache stores private keys of a key management system (KMS) for a plurality of accounts. The computing system performs a cryptographic operation for accessing the database within the secure enclave using the at least one private key. In various embodiments, disclosed techniques may improve the security of cryptographic private keys cached for a plurality of tenants.

Protection of a data file to be used by a white-box cryptography software application installed in memory of a device to prevent the malevolent use of a digital copy of the data file by a white-box cryptography (WBC) software application installed in memory of another device. The mechanism includes extracting an unique identifier for the device from the environment of the device and modifying data in the data file according to the unique identifier, the available white-box cryptography software application includes a software security layer to retrieve the unique identifier from the environment of the device in which the software application is installed and to use this unique identifier in combination with the stored data file when executing, the result of the execution being correct only in case where the correct unique identifier has been extracted by the executed WBC software application.

A novel architecture for a data sharing system (DSS) is disclosed and seeks to ensure the privacy and security of users' personal information. In this type of network, a user's personally identifiable information is stored and transmitted in an encrypted form, with few exceptions. The only key with which that encrypted data can be decrypted, and thus viewed, remains in the sole possession of the user and the user's friends/contacts within the system. This arrangement ensures that a user's personally identifiable information cannot be examined by anyone other than the user or his friends/contacts. This arrangement also makes it more difficult for the web site or service hosting the DSS to exploit its users' personally identifiable information. Such a system facilitates the encryption, storage, exchange and decryption of personal, confidential and/or proprietary data.