diff --git a/SignalServiceKit/src/Contacts/TSThread.m b/SignalServiceKit/src/Contacts/TSThread.m
index f7ef5a92d..b905655c7 100644
--- a/SignalServiceKit/src/Contacts/TSThread.m
+++ b/SignalServiceKit/src/Contacts/TSThread.m
@@ -75,8 +75,9 @@ NS_ASSUME_NONNULL_BEGIN
 #pragma mark To be subclassed.
 
 - (BOOL)isGroupThread {
-    OWSFail(@"An abstract method on TSThread was called.");
-    return FALSE;
+    OWS_ABSTRACT_METHOD();
+
+    return NO;
 }
 
 // Override in ContactThread
@@ -86,13 +87,15 @@ NS_ASSUME_NONNULL_BEGIN
 }
 
 - (NSString *)name {
-    OWSFail(@"Should be implemented in subclasses");
+    OWS_ABSTRACT_METHOD();
+
     return nil;
 }
 
 - (NSArray<NSString *> *)recipientIdentifiers
 {
-    OWSFail(@"Should be implemented in subclasses");
+    OWS_ABSTRACT_METHOD();
+
     return @[];
 }
 
diff --git a/SignalServiceKit/src/Util/Cryptography.h b/SignalServiceKit/src/Util/Cryptography.h
index f0369969d..e6d00487d 100755
--- a/SignalServiceKit/src/Util/Cryptography.h
+++ b/SignalServiceKit/src/Util/Cryptography.h
@@ -34,7 +34,7 @@ typedef NS_ENUM(NSInteger, TSMACType) {
     TSHMACSHA256AttachementType  = 3
 };
 
-+ (NSMutableData *)generateRandomBytes:(NSUInteger)numberBytes;
++ (NSData *)generateRandomBytes:(NSUInteger)numberBytes;
 
 #pragma mark SHA and HMAC methods
 
diff --git a/SignalServiceKit/src/Util/Cryptography.m b/SignalServiceKit/src/Util/Cryptography.m
index eefac4f78..e4cea1a2d 100755
--- a/SignalServiceKit/src/Util/Cryptography.m
+++ b/SignalServiceKit/src/Util/Cryptography.m
@@ -8,6 +8,7 @@
 #import "OWSError.h"
 #import <CommonCrypto/CommonCryptor.h>
 #import <CommonCrypto/CommonHMAC.h>
+#import <Curve25519Kit/Randomness.h>
 #import <openssl/evp.h>
 
 #define HMAC256_KEY_LENGTH 32
@@ -99,16 +100,9 @@ const NSUInteger kAES256_KeyByteLength = 32;
 
 #pragma mark random bytes methods
 
-+ (NSMutableData *)generateRandomBytes:(NSUInteger)numberBytes {
-    /* used to generate db master key, and to generate signaling key, both at install */
-    NSMutableData *randomBytes = [NSMutableData dataWithLength:numberBytes];
-    int err = SecRandomCopyBytes(kSecRandomDefault, numberBytes, [randomBytes mutableBytes]);
-    if (err != noErr) {
-        DDLogError(@"Error in generateRandomBytes: %d", err);
-        @throw
-            [NSException exceptionWithName:@"random problem" reason:@"problem generating random bytes." userInfo:nil];
-    }
-    return randomBytes;
++ (NSData *)generateRandomBytes:(NSUInteger)numberBytes
+{
+    return [Randomness generateRandomBytes:numberBytes];
 }
 
 #pragma mark SHA1