Patent ID: 11870891
Assignee: SECURED-IC SAS
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. The receiver device of claim 4, wherein the first ciphertext set comprises a first ciphertext, a second ciphertext, a third ciphertext, a fourth ciphertext, and a fifth ciphertext, the receiver device being configured to randomly generate a random secret key, the receiver device being configured to determine a transmitter public key by applying the first cryptographic hash function to the transmitter device identifier, and to determine a first intermediate value by applying a third cryptographic hash function to said random secret key, to the first public session key, and to the second public session key, the receiver device being further configured to:
determine said first ciphertext by applying an exponentiation function of a basis equal to a trusted user public key and an exponent equal to said first intermediate value;
add said random secret key to a value, which provides said second ciphertext, said value being a result a second cryptographic hash function applied to the output of the bilinear map applied to a first input and a second input, said first input being the result of an exponentiation function having a basis given by a transmitter device public key and an exponent given by said intermediate value, said second input being of the result of the first cryptographic hash function to applied to the trusted center identifier;
determine said third ciphertext by applying a cipher algorithm to the first public session key, said cipher algorithm using said random secret key as encryption key;
determine said fourth ciphertext by applying a cipher algorithm to the second public session key; and
determine said fifth ciphertext by applying a second cryptographic hash function to the output of an application of a bilinear map exponent said first intermediate value, said output being obtained by applying said bilinear map to the receiver partial private key and the transmitter public key.