Techniques for determining whether a public encryption key is vulnerable as the result of deficiencies in pseudorandom number generation algorithms are provided. In some embodiments, a system may compile a database of cryptographic information received from a plurality of sources, including databases, and network traffic monitoring tools. RSA public keys extracted from the cryptographic information may be stored in an organized database in association with corresponding metadata. The system may construct a product tree from all unique collected RSA keys, and may then construct a remainder tree from the product tree, wherein each output remainder may be determined to be a greatest common divisor of one of the RSA keys against all other unique RSA keys in the database. The system may then use the greatest common divisors to factor one or more of the RSA keys and to determine that the factored keys are vulnerable to being compromised.

An example operation may include one or more of dividing a data file into a plurality of data chunks, generating a randomness value for each data chunk based on one or more predefined randomness tests, and accumulating generated randomness values of the plurality of data chunks to generate an accumulated randomness value, detecting whether the data file is one or more of encrypted and compressed based on the accumulated randomness value and a predetermined threshold value, and storing information about the detection via a storage.

A secret key estimation device is provided for determining an estimate of at least one secret key used during a number of executions of a cryptographic function used by at least one cryptographic algorithm. The number of executions of the cryptographic function is at least equal to two. The secret key estimation device comprises an analysis unit for determining a plurality of sets of leakage traces from a side-channel information acquired during the number of executions of the cryptographic function. Each set of leakage traces corresponds to an execution of the cryptographic function and comprising at least one leakage trace. The secret key estimation device further comprises a processing unit configured to determine a statistical distribution of the acquired plurality of sets of leakage traces. The statistical distribution is dependent on a leakage function, the leakage function being represented in a basis of functions by a set of real values. The secret key estimation device is configured to determine the secret key from the statistical distribution of the plurality of sets of leakage traces using an estimation algorithm according to the maximization of a performance metric.

Techniques for calculating a hash value of a single secure array of memory blocks in a sequential set of dice. The array can be defined by a set of address-size pairs. Each pair provides a pointer by including an address of a memory block and a size of the block. The hash value can be calculated by: for each die that is not the last die, partially applying a hash function, without final padding, to the memory blocks of the secure array in the die to generate a partial digest. And, for the last die, fully applying the hash function, with the final padding, to the memory blocks of the secure array in the last die to generate the hash value of the secure array, which can include adding an accumulation of partial digests to data from the last die as a basis for the generation of the hash value.

A plurality of dice having at least a first die and a second die. The first die can generate a measure of the first die using a cryptographic algorithm, a public key and a private key, and a digital signature according to the measure and the private key. The digital signature can include a digest encrypted by the private key. The digest can include the measure. The first die can communicate the measure, the digital signature, and the public key to the second die. The second die can store a validation code representative of a measure of the first die and validate the digital signature using the public key as well validate the measure by comparing the measure to the validation code.

This disclosure describes techniques for analyzing statistical quality of bitstrings produced by a physical unclonable function (PUF). The PUF leverages resistance variations in the power grid wires of an integrated circuit. Temperature and voltage stability of the bitstrings are analyzed. The disclosure also describes converting a voltage drop into a digital code, wherein the conversion is resilient to simple and differential side-channel attacks.

A physical cryptocurrency may comprise a physical medium and an attached processor. The processor may generate a public-private key pair, or the public-private key pair may be generated in a secure and auditable manner external to the processor and stored on the processor. The private key may enable execution of a smart contract on a blockchain to transfer an asset from a starting address to a destination address on the blockchain.

Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for recovering and verifying a public key. One of the methods includes accepting information encoding parameters of an elliptic curve, a published public key, a hash value of a message, a digital signature, and an identification parameter; generating a recovered public key based on the parameters of the elliptic curve, the hash value of the message, the digital signature, and the identification parameter; comparing the published public key and the recovered public key to verify the published public key.

Smart contract code is verified by storing smart contract code, identifying a type system for verifying a determinism of the smart contract code based on a first set of security-level values and a second set of security level values, and verifying the determinism of the smart contract code by taking the first set of security-level values as deterministic values and the second set of security level values as non-deterministic values.

A system and method for minimizing the likelihood that the secret key used by a bootloader is compromised is disclosed. A bootloader is installed on the device. The bootloader is a software program that performs many functions. These functions may include checking the checksum of the incoming software image for integrity, decrypting the incoming software image using a secret key, deleting data in the FLASH memory, installing the new software image in the FLASH memory and other functions. The bootloader utilizes various techniques to track the versions of the software image being installed. The method counts the number of incomplete attempts that are made when trying to update the software image. By monitoring these parameters, the bootloader can determine when a malicious actor is attempting a side channel attack. In response, the bootloader may not allow a new software image to be loaded or the secret key to be accessed.