Blakley

Blakley may refer to a surname or to a cryptographic secret sharing scheme named after its designer. The surname Blakley is of English origin and has been borne by several individuals in the United States and other English-speaking countries. A notable figure is George R. Blakley, an American cryptographer who introduced the Blakley secret sharing scheme in 1979.

The Blakley secret sharing scheme is a threshold cryptographic method for distributing a secret among a group of participants. In this scheme, the secret is represented as a point in a finite-dimensional space. Each participant receives a share that is a hyperplane equation which passes through the secret. Any group of at least t shares can reconstruct the secret by solving the resulting system of linear equations formed by the t hyperplanes. Fewer than t shares do not allow unique reconstruction, and consequently do not reveal the secret, assuming random selection of the hyperplanes subject to passing through the secret. The construction operates over finite fields and provides information-theoretic security with the appropriate parameters.

Historically, Blakley’s approach offers a geometric alternative to secret sharing schemes based on polynomials, such as Shamir’s scheme from the same era. Applications of Blakley-style secret sharing include secure multiparty computation, distributed key management, and fault-tolerant data storage, where a secret must be recoverable only when a sufficient number of participants cooperate.

See also discussions of threshold schemes and other secret sharing techniques, which compare the geometric perspective of Blakley with the algebraic approach of Shamir.