US 11,750,363 B2
Privacy-preserving domain name service (DNS)
Bogdan C. Cebere, Buchare (RO); Elena Burceanu, Buchare (RO); Madalina Bolboceanu, Focsani (RO); Emanuela Haller, Buchare (RO); Georgiana M. Rosca, Buchare (RO); and Radu Titiu, Buchare (RO)
Assigned to Bitdefender IPR Management Ltd., Nicosia (CY)
Filed by Bitdefender IPR Management Ltd., Nicosia (CY)
Filed on Nov. 4, 2020, as Appl. No. 16/949,587.
Prior Publication US 2022/0140996 A1, May 5, 2022
Int. Cl. H04L 9/00 (2022.01); G06F 16/22 (2019.01); H04L 9/32 (2006.01); H04L 61/2539 (2022.01); H04L 61/4511 (2022.01)
CPC H04L 9/008 (2013.01) [G06F 16/2255 (2019.01); H04L 9/3213 (2013.01); H04L 61/2539 (2013.01); H04L 61/4511 (2022.05)] 19 Claims
OG exemplary drawing
 
1. A method of performing a domain name service (DNS) lookup comprising employing at least one hardware processor of a computer system to:
in response to receiving an indicator of a domain name, determine whether a privacy condition is satisfied according to the domain name, wherein the domain name comprises a sequence of tokens, and wherein determining whether the privacy condition is satisfied comprises determining whether a selected token of the sequence of tokens matches any member of a reference list of tokens;
in response to determining that the privacy condition is satisfied, formulate a private query comprising an encryption of a hash index indicative of a location of a record within a domain name database, the hash index encrypted according to a homomorphic encryption procedure, wherein the hash index is determined according to the domain name, and wherein the private query further comprises a version indicator indicative of a hash function used in calculating the hash index;
in response to formulating the private query, transmit the private query to a nameserver configured to determine whether the domain name data is currently indexed according to the hash function, and in response to the hash function, perform an encrypted lookup into the domain name database according to the private query, producing an encryption of the record; and
in response to receiving a private reply comprising the encryption of the record from the nameserver, decrypt a content of the private reply according to a homomorphic decryption procedure.