1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
// Copyright 2018 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tink
/*
DeterministicAEAD is the interface for deterministic authenticated encryption with associated data.
Warning:
Unlike AEAD, implementations of this interface are not semantically secure, because
encrypting the same plaintext always yields the same ciphertext.
Security guarantees:
Implementations of this interface provide 128-bit security level against multi-user attacks
with up to 2^32 keys. That means if an adversary obtains 2^32 ciphertexts of the same message
encrypted under 2^32 keys, they need to do 2^128 computations to obtain a single key.
Encryption with associated data ensures authenticity (who the sender is) and integrity (the
data has not been tampered with) of that data, but not its secrecy.
References:
* https://tools.ietf.org/html/rfc5116
* https://tools.ietf.org/html/rfc5297#section-1.3
*/
type DeterministicAEAD interface {
// EncryptDeterministically deterministically encrypts plaintext with associatedData as
// associated authenticated data.
//
// Warning:
// Encrypting the same plaintext multiple times protects the integrity of that plaintext,
// but confidentiality is compromised to the extent that an attacker can determine that
// the same plaintext was encrypted.
//
// The resulting ciphertext allows for checking authenticity and integrity of associatedData,
// but does not guarantee its secrecy.
EncryptDeterministically(plaintext, associatedData []byte) ([]byte, error)
// DecryptDeterministically deterministically decrypts ciphertext with associatedData as
// associated authenticated data. The decryption verifies the authenticity and integrity
// of the associated data, but there are no guarantees with respect to secrecy of that data.
DecryptDeterministically(ciphertext, associatedData []byte) ([]byte, error)
}
|
