International Business Machines Corporation

Miguel Angel Prada Delgado

Alessandro Sorniotti

Elli Androulaki

Gero Dittmann

Marko Vukolić

Marc Ph Stoecklin

Ilie Circiumaru

Jesus Diaz Vico

An example operation may include one or more of extracting a data object from a machine-readable code. The data object can include fields of data signed with a digital signature of a private key, detecting an identifier of an issuer of the data object from the extracted data object, retrieving a public key from a blockchain based on the identifier of the issuer detected from the field of the extracted data object, and verifying the digital signature of the private key based on the fetched public key.

Blockchain based verifiability of user status

Methods are provided for generating a random bit-string from an array of SRAM cells. Such a method includes reading the start-up value of each cell over multiple power-ups of the array, and calculating, from the multiple start-up values of each cell, a bias value indicative of entropy of that cell. The method also includes generating, based on the bias values, an address list in which addresses of cells in the array are listed in order of entropy of the cells. This address list is stored in non-volatile memory. The method further comprises, on a subsequent power-up of the array, generating a random bit-string by reading the start-up values of a set of cells selected in decreasing entropy order of the address list. Hardware random number generators exploiting such methods are also provided.

Random number generation from SRAM cells

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Rueschlikon, Switzerland

Miguel Angel Prada Delgado