Pros of BoringSSL

• More established and widely used in production environments
• Offers a broader range of cryptographic primitives and protocols
• Actively maintained by Google with frequent updates and security patches

Cons of BoringSSL

• Larger codebase and more complex API, potentially steeper learning curve
• Less focus on ease of use and high-level abstractions
• May require more cryptographic expertise to use correctly and securely

Code Comparison

BoringSSL (low-level API):

EVP_CIPHER_CTX *ctx;
EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv);
EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len);
EVP_EncryptFinal_ex(ctx, ciphertext + len, &len);

Tink (high-level API):

AeadKeyTemplate keyTemplate = AeadKeyTemplates.AES256_GCM;
KeysetHandle keysetHandle = KeysetHandle.generateNew(keyTemplate);
Aead aead = keysetHandle.getPrimitive(Aead.class);
byte[] ciphertext = aead.encrypt(plaintext, associatedData);

BoringSSL provides a lower-level API requiring more manual management, while Tink offers a higher-level abstraction with built-in key management and simpler usage patterns. BoringSSL is more suitable for projects needing fine-grained control over cryptographic operations, whereas Tink is designed for easier integration and reduced risk of misuse in application-level cryptography.

Pros of Wycheproof

• Focused on cryptographic test vectors, providing a comprehensive suite for testing implementations
• Language-agnostic approach, allowing for broader application across different programming languages
• Regularly updated with new test vectors for emerging cryptographic algorithms and protocols

Cons of Wycheproof

• Limited to testing and doesn't provide a full cryptographic library implementation
• Requires integration with existing cryptographic libraries for practical use
• May have a steeper learning curve for developers not familiar with cryptographic testing methodologies

Code Comparison

Tink example (Java):

KeysetHandle keysetHandle = KeysetHandle.generateNew(AeadKeyTemplates.AES128_GCM);
Aead aead = keysetHandle.getPrimitive(Aead.class);
byte[] ciphertext = aead.encrypt(plaintext, associatedData);

Wycheproof example (JSON test vector):

{
  "algorithm" : "AES-GCM",
  "generatorVersion" : "0.0",
  "numberOfTests" : 15,
  "testGroups" : [
    {
      "ivSize" : 96,
      "keySize" : 128,
      "tagSize" : 128,
      "type" : "AesGcmTest",
      "tests" : [
        {
          "tcId" : 1,
          "comment" : "valid test vector",
          "key" : "5b9604fe14eadba931b0ccf34843dab9",
          "iv" : "26aa49dcfe7a79b320b66d39",
          "aad" : "",
          "msg" : "28286a321293253c3e0aa2704a278032",
          "ct" : "5a3c1cf1985dbb8bed818036fdd5ab42",
          "tag" : "23c7ab0f952b7091cd324835043b5eb5",
          "result" : "valid"
        },
        // ... more test cases ...
      ]
    }
  ]
}

Pros of End-to-End

• Focuses specifically on end-to-end encryption for email and other communications
• Provides a user-friendly interface for managing encrypted communications
• Integrates well with existing email clients and web browsers

Cons of End-to-End

• Less actively maintained compared to Tink
• Limited to specific use cases (primarily email encryption)
• Smaller community and fewer contributors

Code Comparison

End-to-End (JavaScript):

goog.require('e2e.openpgp.asciiArmor');
goog.require('e2e.openpgp.block.factory');

var armoredText = '-----BEGIN PGP MESSAGE-----\n...';
var block = e2e.openpgp.block.factory.parseAsciiArmored(armoredText);

Tink (Java):

import com.google.crypto.tink.*;

KeysetHandle keysetHandle = KeysetHandle.generateNew(AeadKeyTemplates.AES128_GCM);
Aead aead = keysetHandle.getPrimitive(Aead.class);
byte[] ciphertext = aead.encrypt(plaintext, associatedData);

Tink offers a more comprehensive and actively maintained cryptographic library with support for various primitives, while End-to-End focuses specifically on OpenPGP-based email encryption. Tink provides a simpler API for common cryptographic operations, whereas End-to-End offers more specialized functionality for secure communications.

Pros of Keyczar

• Simpler API with fewer concepts to learn
• Supports a wider range of key types, including DSA
• Better suited for legacy systems and applications

Cons of Keyczar

• Less actively maintained (last commit in 2018)
• Limited language support (primarily Java and Python)
• Lacks modern cryptographic primitives and algorithms

Code Comparison

Keyczar (Java):

Crypter crypter = new Crypter("path/to/keys");
String ciphertext = crypter.encrypt("Hello, World!");
String plaintext = crypter.decrypt(ciphertext);

Tink (Java):

KeysetHandle keysetHandle = KeysetHandle.generateNew(AeadKeyTemplates.AES128_GCM);
Aead aead = AeadFactory.getPrimitive(keysetHandle);
byte[] ciphertext = aead.encrypt("Hello, World!".getBytes(), null);
byte[] plaintext = aead.decrypt(ciphertext, null);

Tink offers a more flexible and modular approach, with stronger type safety and better support for key management. It also provides more advanced features like key rotation and multi-language support. However, Keyczar's simplicity may be preferable for smaller projects or those with simpler cryptographic needs.

Pros of libsodium

• Mature and widely adopted cryptographic library with a focus on simplicity and ease of use
• Extensive cross-platform support, including mobile and embedded systems
• Provides a comprehensive set of low-level cryptographic primitives

Cons of libsodium

• Requires more cryptographic expertise to use correctly compared to Tink's higher-level abstractions
• Less emphasis on key management and rotation features
• Smaller ecosystem of language bindings and integrations

Code Comparison

libsodium example (encryption):

unsigned char ciphertext[crypto_secretbox_MACBYTES + MESSAGE_LEN];
crypto_secretbox_easy(ciphertext, message, MESSAGE_LEN, nonce, key);

Tink example (encryption):

Aead aead = AeadFactory.getPrimitive(keysetHandle);
byte[] ciphertext = aead.encrypt(plaintext, associatedData);

Both libraries provide cryptographic operations, but Tink offers a higher-level API with built-in key management and rotation features. libsodium provides more fine-grained control over cryptographic primitives, while Tink focuses on simplifying secure usage through abstraction. The choice between them depends on the specific requirements of the project and the level of cryptographic expertise available.

Pros of OpenSSL

• Extensive feature set covering a wide range of cryptographic operations
• Long-standing industry standard with widespread adoption and support
• Highly performant and optimized for various platforms

Cons of OpenSSL

• Complex API with a steep learning curve
• Requires careful usage to avoid security pitfalls
• Frequent updates and patches needed to address vulnerabilities

Code Comparison

OpenSSL example (encryption):

EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();
EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, key, iv);
EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len);
EVP_EncryptFinal_ex(ctx, ciphertext + len, &len);

Tink example (encryption):

Aead aead = AeadFactory.getPrimitive(keysetHandle);
byte[] ciphertext = aead.encrypt(plaintext, associatedData);

Tink offers a simpler API with built-in security best practices, while OpenSSL provides more granular control but requires careful implementation. OpenSSL's extensive feature set and performance make it suitable for a wide range of applications, whereas Tink focuses on ease of use and reducing the risk of misuse in cryptographic operations.