Abstract: Various additional and alternative aspects are described herein. In some aspects, the present disclosure provides a method of authenticating executable images in a system-on-chip (SoC), the method comprising: storing a plurality of executable images; storing, as separate from the plurality of executable images, a signed image of hashes comprising a plurality of hashes corresponding to the plurality of executable images and a first signature; authenticating the signed image of hashes based on the first signature; and using a first hash of the plurality of hashes to authenticate a first executable image of the plurality of executable images when the signed image of hashes passes authentication.

Abstract: A method of implementing security in a modular exponentiation function for cryptographic operations is provided. A key is obtained as a parameter when the modular exponentiation function is invoked. The key may be one of either a public key or a private key of a cryptographic key pair. Within the modular exponentiation function, the method ascertains whether the key is greater than L bits long, where L is a positive integer. A countermeasure against an attack is implemented if the key is greater than L bits long. The countermeasure may include one or more techniques (e.g., hardware and/or software techniques) that inhibit or prevent information about the key from being ascertained through analysis. One or more exponentiation operations may then be performed using the key. The same modular exponentiation function may be used to perform encryption and decryption operations but with different keys.

Abstract: Various additional and alternative aspects are described herein. In some aspects, the present disclosure provides a method of authenticating executable images in a system-on-chip (SoC), the method comprising: storing a plurality of executable images; storing, as separate from the plurality of executable images, a signed image of hashes comprising a plurality of hashes corresponding to the plurality of executable images and a first signature; authenticating the signed image of hashes based on the first signature; and using a first hash of the plurality of hashes to authenticate a first executable image of the plurality of executable images when the signed image of hashes passes authentication.

Abstract: Techniques for authenticating data on a computing device are provided. An example method according to these techniques includes generating a first cryptographic output by applying a first cryptographic algorithm to each block of a first subset of the plurality of blocks of data to be authenticated, combining a last block of the first cryptographic output with a second subset of the plurality of blocks of data to generate an intermediate result, and generating an authentication output by applying a second cryptographic algorithm to the intermediate result, the second cryptographic algorithm being different than the first cryptographic algorithm.

Abstract: A method of implementing security in a modular exponentiation function for cryptographic operations is provided. A key is obtained as a parameter when the modular exponentiation function is invoked. The key may be one of either a public key or a private key of a cryptographic key pair. Within the modular exponentiation function, the method ascertains whether the key is greater than L bits long, where L is a positive integer. A countermeasure against an attack is implemented if the key is greater than L bits long. The countermeasure may include one or more techniques (e.g., hardware and/or software techniques) that inhibit or prevent information about the key from being ascertained through analysis. One or more exponentiation operations may then be performed using the key. The same modular exponentiation function may be used to perform encryption and decryption operations but with different keys.