Encryption schemes with additional properties
First Claim
Patent Images
1. A method of encrypting a message m using a Paillier cryptosystem, comprising:
- computing a ciphertext c based upon the message m, N, and r, where N is the product of two distinct primes p and q, and r is randomly chosen such that r∈
[1, N);
computing a first verification value based upon u and N, where u is randomly chosen such that u∈
[1, N); and
computing a second verification value s based upon u, r, the ciphertext c, the verification value, and a hash function H,wherein U=uN mod N where U is the first verification value, andwherein s=u re mod N and where e=H (c, U).
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Abstract
Various embodiments relate to a method of encrypting a message m using a Paillier cryptosystem, including: computing a ciphertext c based upon the message m, N, and r, where N is the product of two distinct primes p and q, and r is randomly chosen such that r∈[1, N); computing a first verification value based upon u and N, where u is randomly chosen such that u∈[1, N); computing a second verification value s based upon u, r, the ciphertext c, the verification value, and a hash function H.
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Citations
16 Claims
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1. A method of encrypting a message m using a Paillier cryptosystem, comprising:
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computing a ciphertext c based upon the message m, N, and r, where N is the product of two distinct primes p and q, and r is randomly chosen such that r∈
[1, N);computing a first verification value based upon u and N, where u is randomly chosen such that u∈
[1, N); andcomputing a second verification value s based upon u, r, the ciphertext c, the verification value, and a hash function H, wherein U=uN mod N where U is the first verification value, and wherein s=u re mod N and where e=H (c, U). - View Dependent Claims (2, 3, 10)
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4. A method of encrypting a message m using a Paillier cryptosystem, comprising:
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computing a ciphertext c based upon the message m, N, and r, where N is the product of two distinct primes p and q, and r is randomly chosen such that r∈
[1,N);computing a first verification value based upon u and N, where u is randomly chosen such that u∈
[1,N); andcomputing a second verification value s based upon u, r, the ciphertext c, the verification value, and a hash function H, wherein V=H(uN mod N) where V is the first verification value. - View Dependent Claims (5, 6)
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7. A method of encrypting a message m using a Paillier cryptosystem, comprising:
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computing a ciphertext c based upon the message m, N, and r, where N is the product of two distinct primes p and q, and r is randomly chosen such that r∈
[1,N);computing a first verification value based upon u and N, where u is randomly chosen such that u∈
[1,N); andcomputing a second verification value s based upon u, r, the ciphertext c, the verification value, and a hash function H, wherein V=G(uN mod N) where V is the first verification value and G is a hash function different from hash function H. - View Dependent Claims (8, 9)
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11. A method of decrypting a ciphertext using a Paillier cryptosystem including a value c, a first verification value, and a second verification value s, comprising:
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validating the ciphertext by checking the first verification value based upon the second verification value s, N, the value c, and a hash function H, where N is the product of two distinct primes p and q; deciphering the ciphertext to produce a message m from the value c using a secret key and N; computing e=H(c, V) and U=sNc−
e mod N, where V is first verification value; andchecking that the first verification value V equals H(U). - View Dependent Claims (13, 14, 16)
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12. A method of decrypting a ciphertext using a Paillier cryptosystemincluding a value c, a first verification value, and a second verification value s, comprising:
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validating the ciphertext by checking the first verification value based upon the second verification value s, N, the value c, and a hash function H, where N is the product of two distinct primes p and q; deciphering the ciphertext to produce a message m from the value c using a secret key and N; computing e=H (c, V) and U=sNc−
e mod N, where V is first verification value; andchecking that the first verification value V equals G (U), where G is a hash function different from hash function H.
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15. A method of decrypting a ciphertext using a Paillier cryptosystemincluding a value c, a first verification value, and a second verification value s, comprising:
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validating the ciphertext by checking the first verification value based upon the second verification value s, N, the value c, and a hash function H, where Nis the product of two distinct primes p and q; deciphering the ciphertext to produce a message m from the value c using a secret key and N; computing e=H (c, U), where U is verification value; and checking that the verification value U equals sNc−
e mod N.
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Specification